1. In triangle ABC. A-54.2° B=71.5º, a=12 4cm. Find b

Answers

Answer 1

Answer:

13

Step-by-step explanation:


Related Questions

7 - 5x > 3x + 31
A.X2-3 (all numbers greater than or equal to -3 will satisfy the inequality)B.xs-3 (all numbers less than or equal to -3 will satisfy the inequality)
C.X26 (all numbers greater than or equal to 6 will satisfy the inequality)
D.xs 6 (all numbers less than or equal to 6 will satisfy the inequality)

Answers

Answer: B. (all numbers less than or equal to -3 will satisfy the inequality)

Step-by-step explanation:

Hi, to answer this question we have to solve the inequality for x:

7 - 5x > 3x + 31

7-31 > 3x +5x

-24 > 8x

-24/8 > x

-3 > x

x < -3

So, the correct option is:

B. (all numbers less than or equal to -3 will satisfy the inequality)

Feel free to ask for more if needed or if you did not understand something.

sample of 64 observations is selected from a normal population. The sample mean is 215, and the population standard deviation is 15. Conduct the following test of hypothesis using the 0.025 significance level. H0: μ ≥ 220 H1: μ < 220 Is this a one- or two-tailed test? One-tailed test Two-tailed test

Answers

Answer: (upside down fancy u) q5

Step-by-step explanation:

Simply apply the law of conservative (upside down fancy u)

Need help with these last two questions, tysm if you do :D

Answers

Answer:

D.

A. x ≤ 1

Step-by-step explanation:

Well for the first question we need to simplify the inequality.

4x + 3 < x - 6

-x to both sides

3x + 3 < -6

-3 to both sides

3x < -9

Divide 3

x < -3

So if x is less than -3 than it goes to the left starting at -3.

So D. is the answer.

So to solve the floowing inequality we simplify, distribute, and combine like terms.

3(2x - 5) + 3 ≤ -2(x + 2)

6x - 15 + 3 ≤ -2x -4

6x -12 ≤ -2x - 4

8x - 12 ≤ -4

+12

8x ≤ 8

8/8

x ≤ 1

Hence the answer is A. x ≤ 1

WHAT IS THE ANSWER PLS HELPPPPP!!!!!

Answers

Answer:

5^x - 5^-x

Step-by-step explanation:

g(x) = 5^-x

h(x) = 5^x

We want h(x) - g(x)

h(x) - g(x) = 5^x - 5^-x

This cannot be simplified

Help me please!!!!!!!!!!

Answers

Answer:

Option (4)

Step-by-step explanation:

In the picture attached,

m∠NLM = m∠LKN = 90°

In two similar triangles ΔLKN and ΔMKL,

By the property of similar triangles,

"Ratio of the corresponding sides of the similar triangles are proportional".

[tex]\frac{\text{LK}}{\text{KN}}=\frac{\text{KM}}{\text{LK}}[/tex]

By substituting the values given,

[tex]\frac{h}{3}=\frac{2}{h}[/tex]

[tex]\frac{2}{h}=\frac{h}{3}[/tex]

Therefore, Option (4) will be the answer.

In a class Vidya ranks 7th from the top. Divya
is 7 ranks ahead of Medha and 3 ranks
behind Vidya. Sushma who is 4th from the
bottom is 32 ranks behind Medha. How many
students are there in the class?​

Answers

Answer:

52 students

Step-by-step explanation:

From the question above, we have the following information:

a) Vidya ranks 7th from the top.

Mathematically,

Vidya = 7th student

b) Divya 3 ranks behind Vidya.

Divya = Vidya + 3

Hence, Mathematically:

Divya = 7 + 3 = 10

Divya = 10th student

c) Also, Divya is 7 ranks ahead of Medha.

Mathematically,

Medha = 10 + 7= 17

Medha= 17th student

d)Sushma is 32 ranks behind Medha

Mathematically,

Sushma = Medha + 32

= 17 + 32 = 49

Sushma is the 49th student

Therefore, since, Sushma is 4th from the bottom, total number of students is:

49 + 3 = 52 students

Please help. First person to answer correctly with explanation will get brainiest!!!

Answers

Answer:

64° aka D

Step-by-step explanation:

∠J + ∠L + ∠LKJ = 180°

58° + 58° + ∠LKJ = 180°

116° + ∠LKJ = 180°

∠LKJ = 180° - 116°

=  64°

hope i helped

-lvr

P(x) has factors (x-2), (x+1), and (x-3). Decide if there is only one polynomial that has these factors. Justify your answer.

Answers

Answer:

See explanation

Step-by-step explanation:

if multiply the 3 factors together you get

(x² - x - 2)(x - 3) - trinomial x binomial

x³ - 3x²- x² + 3x - 2x + 6 - polynomial

x³ - 4x² + x + 6, this is the polynomial with those factors.

Poly means many so it could be a bigger polynomial with more factors but if it is limited to only these factors than there is just the one polynomial.

The polynomial is x³ - 4x² + x + 6 with factors (x-2), (x+1), and (x-3)

What is polynomial?

A polynomial is the defined as mathematical expression that have a minimum of two terms containing variables or numbers. A polynomial can have more than one term.

What are Arithmetic operations?

Arithmetic operations can also be specified by subtracting, dividing, and multiplying built-in functions. The operator that performs the arithmetic operation is called the arithmetic operator.

Operators which let do a basic mathematical calculation

+ Addition operation: Adds values on either side of the operator.

For example 12 + 2 = 14

- Subtraction operation: Subtracts the right-hand operand from the left-hand operand.

for example 12 -2 = 10

* Multiplication operation: Multiplies values on either side of the operator

For example 12*2 = 24

Given that ,

P(x) has three factors (x-2), (x+1), and (x-3).

Multiplying the 3 factors together, we get

⇒ (x-2)(x+1)(x-3)

⇒ [x(x-3) - 2(x+1)](x-3)

⇒ (x² - x - 2)(x - 3)

⇒ x³ - 3x²- x² + 3x - 2x + 6

Rearrange the terms likewise and apply arithmetic operations

x³ - 4x² + x + 6

Hence, the polynomial is x³ - 4x² + x + 6 with factors (x-2), (x+1), and (x-3).

Learn more about polynomial here:

https://brainly.com/question/11536910

#SPJ2

I need help please answer ASAP Have a good explination.
Will give brainliest

Answers

Answer and Step-by-step explanation:

When two triangles are congruent they will have exactly the same three sides and exactly the same three angles. The equal sides and angles may not be in the same position (if there is a turn or a flip), but they are there.

Now let's solve by using this statement..

1. Yes they are, cause they have excatly the same three sides and excatly the same three angles.

2. no they are not, cause they do not have excatly the same three sides and excatly the same three angles.

3. Yes they are, cause they have excatly the same three sides and excatly the same three angles.

4. Yes they are, cause they have excatly the same three sides and excatly the same three angles.

5. Yes they are, cause they have excatly the same three sides and excatly the same three angles.

6. Yes they are, cause they have excatly the same three sides and excatly the same three angles.

Hope this helped... If yes plz mark as BRAINLIEST and follow me.

Tysmm!!!

Find the Equation of the Parallel Line
2
of
Instructions: Find the equation of the line through point (-7,2) and parallel to
= x - 1. Use a forward slash (i.e. "/") for fractions (e.g. 1/2 for 1).
Y=
y =

Answers

Answer:

y = 2/5x + 4/5

Step-by-step explanation:

We'll begin by calculating the slope of the equation: y = 2/5x – 1/2

The slope of the above equation can be obtained as follow:

y = mx + c

Where m is the slope.

c is the y-intercept.

y and x are the coordinate.

Comparing:

y = 2/5x – 1/2 with y = mx + c

The slope of y = 2/5x – 1/2 is 2/5.

Now, let us determine the equation parallel to y = 2/5x – 1/2.

This is illustrated below:

The coordinate of the line => (–7, 2)

x1 = –7

y1 = 2

Slope (m) = 2/5 => Since the lines are parallel, their slope are equal.

y – y1 = m (x – x1)

y – 2 = 2/5(x – –7)

y – 2 = 2/5(x + 7)

Clear bracket

y – 2 = 2/5x + 14/5

Rearrange

y = 2/5x + 14/5 + 2

y = 2/5x + 4/5

Therefore, the equation is:

y = 2/5x + 4/5

Peter walked 10m from X to Y on bearing 020° and then he turned and walked 20m to Z with bearing 140° of Z from Y. Find the distance between X and Z. Find the bearing of Z from X.

Answers

Answer:

17.32m ; 110°

Step-by-step explanation:

Distance between X and Z

To calculate the distance between X and Z

y^2 = x^2 + z^2 - (2xz)*cosY

x = 20, Z = 10

y^2 = 20^2 + 10^2 - (2*20*10)* cos60°

y^2 = 400 + 100 - (400)* 0.5

y^2 = 500 - 200

y^2 = 300

y = sqrt(300)

y = 17.32m

Bearing of Z from X:

Using cosine rule :

Cos X = (y^2 + z^2 - x^2) / 2yz

Cos X = (300 + 100 - 400) / (2 * 20 '*10)

Cos X = 0 / 400

Cos X = 0

X = cos^-1 (0)

X = 90°

Bearing of Z from X

= 20° + X

= 20° + 90°

= 110°

NEEEED HELPPPPP PLEASEEEEEE Use long division to find the quotient below.
(8x^2 + 4x^2 + 100) - (2x + 5)

Answers

Answer:

[tex]4x^2 - 8x + 20[/tex]

Step-by-step explanation:

The correct equation is:

[tex]8x^3 + 4x^2 + 100[/tex]

We want to divide that by (2x + 5)

To do the long division, divide each term by 2x and then subtract the product of the result and (2x + 5) from the remaining part of the equation.

When you get to 0, you have reached the end of the division.

Whatever term you get from each step of division is part of the quotient.

Go over the steps above carefully while following them below:

Step 1:

Divide [tex]8x^3[/tex] by 2x. You get [tex]4x^2[/tex].

Step 2

Multiply [tex]4x^2[/tex] by (2x + 5)  and subtract from [tex]8x^3 + 4x^2 + 100[/tex]:

[tex]8x^3 + 4x^2 + 100[/tex] - ([tex]8x^3 + 20x^2[/tex]) = [tex]-16x^2 + 100[/tex]

Step 3

Divide [tex]-16x^2[/tex] by 2x. You get [tex]-8x[/tex].

Step 4

Multiply -8x by (2x + 5) and subtract from [tex]-16x^2 + 100[/tex]:

[tex]-16x^2 + 100[/tex] - ([tex]-16x^2 - 40x[/tex]) = 40x + 100

Step 5

Divide 40x by 2x. You get 20.

Step 6

Multiply 20 by (2x + 5) and subtract from 40x + 100:

40x + 100 - (40x + 100) = 0

From the three steps of the division, we got [tex]4x^2[/tex], -8x and 20.

Therefore, the quotient is [tex]4x^2 - 8x + 20[/tex]

Which data distribution would most likely have a mean and median that are not close in value? Bar graph. The horizontal axis is unnumbered. The vertical axis is numbered 0 to 50. The first bar is 8. The second bar is 30. The third bar is 42. The fourth bar is 29. The fifth bar is 9. Bar graph. The horizontal axis is unnumbered. The vertical axis is numbered 0 to 50. The first bar is 21. The second bar is 44. The third bar is 35. The fourth bar is 45. The fifth bar is 20. A bar graph. The horizontal axis is unnumbered. The vertical axis is numbered 0 to 50. The first bar is 38. The second bar is 43. The third bar is 21. The fourth bar is 5. The fifth bar is 1.

Answers

Answer:

The third one.

Step-by-step explanation:

The last bar graph is skewed to the right, since the values of its fourth and fifth bars are way smaller than the values of its first, second, and third graphs. The drastically smaller values pull down the mean of the last bar graph, making it be more different from the median.

Comparatively, bar graphs one and two have approximately symmetrical distributions of numbers on both sides of the central bar. This means that their mean is balanced out on both sides and that neither of them is significantly skewed left or right.

A bar graph. The horizontal axis is unnumbered. The vertical axis is numbered 0 to 50. The first bar is 38. The second bar is 43. The third bar is 21. The fourth bar is 5. The fifth bar is 1 is data distribution would most likely have a mean and median that are not close in value.

We have to determine, which data distribution would most likely have a mean and median that are not close in value.

According to the question,

The mean and the median both reflect the skewing, but the mean reflects it more.

The last bar graph is skewed to the right since the values of its fourth and fifth bars are way smaller than the values of its first, second, and third graphs.

The drastically smaller values pull down the mean of the last bar graph, making it be more different from the median.

The mean and the median are the same. This example has one mode (unimodal), and the mode is the same as the mean and median.

Bar graphs one and two have approximately symmetrical distributions on both sides of the central bar.

This means that their mean is balanced out on both sides and that neither of them is significantly skewed left or right.

Hence, The horizontal axis is unnumbered. The vertical axis is numbered 0 to 50. The first bar is 38. The second bar is 43. The third bar is 21. The fourth bar is 5. The fifth bar is 1.

To know more about Probability click the link given below.

https://brainly.com/question/23044118

How many solutions are there to the equation below?
7(x + 2) = 7x-10
O A. Infinitely many
O B. o
O c. 1

Answers

Hi there! :)

Answer:

B. 0 solutions.

Step-by-step explanation:

Given the equation 7(x + 2) = 7x - 10

Simplify:

7(x + 2) = 7x - 10

Distribute the 7 with the terms inside of the parenthesis:

7x + 14 = 7x - 10

Subtract "7x" and 14 from both sides:

7x - 7x = -10 - 14

0 ≠ - 24. The equation has no solutions.

Answer:

[tex]\boxed{\sf B. \ 0}[/tex]

Step-by-step explanation:

[tex]\sf 7(x + 2) = 7x-10[/tex]

Expand brackets.

[tex]\sf 7x+14 = 7x-10[/tex]

Subtract 7x and 14 from both sides.

[tex]\sf 7x+14 -7x-14= 7x-10-7x-14[/tex]

[tex]\sf 0=-24[/tex]

There are 0 solutions.

Scarlett Squirrel teaches a hula dancing class to young squirrels. 141414 squirrels showed up to class on Monday, 101010 squirrels on Tuesday, 888 squirrels on Wednesday, 101010 squirrels on Thursday, and 121212 squirrels on Friday. Find the mean number of the squirrels

Answers

Answer:

93107

Step-by-step explanation:

add all of the numbers together

divide by 5 since there are 5 numbers

you would get 92106.8

so round that up since you cannot have 1/8 of a squirrel

Hope this helps!!

a fraction is such that the numerator is 2 less than the denominator if you add 3 to the numerator and 5 to the denominator the resulting fraction is 3/5 find the fraction​

Answers

Answer:

The required fraction is 3/5

Answer:  3/5

Step-by-Step Explanation:

Let x represent the denominator of the fraction, then we have [tex]\dfrac{x-2}{x}[/tex]

Now add 3 to the numerator and 5 to the denominator and set it equal to 3/5:

[tex]\dfrac{(x-2)+3}{(x)+5}=\dfrac{3}{5}\\\\\\\text{Simplify:}\\\dfrac{x+1}{x+5}=\dfrac{3}{5}\\\\\\\text{Cross Multiply and solve for x:}\\5(x+1)=3(x+5)\\5x+5=3x+15\\2x=10\\x=5[/tex]

Substitute x = 5 into the original fraction:

[tex]\dfrac{(5)-2}{(5)}\quad =\large\boxed{\dfrac{3}{5}}[/tex]

Is 5.7c-1.5+3.2c=7.8c-1.5+1.1c a one solution problem?

Answers

Answer:

This is NOT a one solution problem.

Step-by-step explanation:

Group all terms with a c in it to the left of the equal sign, and group all numbers to the right of the equal sign.

5.7c-1.5+3.2c=7.8c-1.5+1.1c

5.7c + 3.2c - 7.8c - 1.1c = - 1.5 + 1.5

8.9c - 8.9c = 0

0 = 0

No matter which number you substitute for c, it will always be true. Since you can find infinity of solutions, this is NOT a one solution problem.

II NEED HELP!!!!!!!! Are the graphs of the lines in the pair parallel? Explain. y = 2/3x– 17 4x – 6y = –6 4x-6y=-6 Yes, since the slopes are the same and the y-intercepts are the same. A )No, since the y-intercepts are different. B)No, since the slopes are different. C)Yes, since the slopes are the same and the y-intercepts are different.

Answers

Answer:

A

Step-by-step explanation:

A science fair poster is a rectangle 48 inches long and 36 inches wide. What is the area of the poster in square feet?
Be sure to include the correct unit in your answer.

Answers

Answer:

Whats the formula for the area of a rectangle?

L x W.  48 x 36 =  1728 sq inches.

Then divide by (12 x12 ) = 144 to find square feet

Step-by-step explanation:

MATH PLEASE HELP ME. WILL GIVE BRAINLIEST

Answers

Answer:

The answer is - 17

Step-by-step explanation:

g(x) = 2x³ - 3x + 5

To find g(- 2) substitute the value of - 2 into g(x)

That's

g(- 2) = 2(-2)³ - 3(-2) + 5

= 2(-8) - 3(2) + 5

= - 16 - 6 + 5

= - 17

Hope this helps you

Omar has a gift card for $40.00 at a gift shop. Omar wants to buy a hat for himself for $13.50. For his friends, he would like to buy souvenir
bracelets, which are $3.25 each. All prices include taxes.
Which inequality can be used to solve for how many bracelets Omar can buy?
OA.
3.25x + 13.50 < 40
O B.
3.25x + 13.50 > 40
OC.
13.50X+3.25 < 40
OD
13.50x + 3.25 2 40​

Answers

Answer:

The answer is A- 3.25x + 13.50 < 40

Answer:

13.50X+3.25 < 40

If f(x) = -8x - 6 and g(x) = x+8 , what is (f • g) (- 7)

Answers

Answer: See below

Explanation:

(f • g)(-7) = [-8(-7) -6](-7+8)

= (56 - 6)(1)

= (50)(1) = 50

Answer:

hello:

Step-by-step explanation:

If f(x) = -8x - 6 and g(x) = x+8 ,  (f • g) (- 7)= f(g(-7))

but g(-7)=-7+8=1

(f • g) (- 7)= f(1) =-8(1)-6 =-14

4sinθ – 1 = - 3 for 0<θ< 360

Answers

Answer:

[tex] \theta = 210^\circ [/tex] or [tex] \theta = 330^\circ [/tex]

Step-by-step explanation:

[tex] 4 \sin \theta - 1 = -3 [/tex]

[tex] 4 \sin \theta = -2 [/tex]

[tex] \sin \theta = \dfrac{-2}{4} [/tex]

[tex] \sin \theta = -0.5 [/tex]

For sin θ = 0.5, the reference angle is θ = 30 deg.

[tex] \sin 30^\circ = 0.5 [/tex]

[tex] \theta = 210^\circ [/tex] or [tex] \theta = 330^\circ [/tex]

The perimeter of a rectangle is 141 feet, and the length is twice the width. What are the dimensions ?

Answers

Answer:

The width is 23.5 ft and the length is 47 ft

Step-by-step explanation:

The perimeter of a rectangle is given by

P = 2(l+w)

141 = 2(l+w)

The length is twice the width

l = 2w

141 = 2 ( 2w+w)

141 = 2( 3w)

141 = 6w

Divide each side by 6

141/6 = 6w/6

23.5 = w

l = 2w = 2(23.5) = 47

The width is 23.5 ft and the length is 47 ft

Answer:

[tex]\boxed{Width = 23.5 \ feet}[/tex]

[tex]\boxed{Length = 47 \ feet}[/tex]

Step-by-step explanation:

Let Length be l and Width be w

Perimeter = 2(Length) + 2(Width)

Condition # 1:

2l+2w = P

=> 2 l + 2 w = 141

Condition # 2:

=> l = 2w

Putting the second equation in the first one

=> 2(2w)+2w = 141

=> 4w + 2w = 141

=> 6w = 141

Dividing both sides by 6

=> Width = 23.5 feet

Given that

=> l = 2w

=> l = 2(23.5)

=> Length = 47 feet

Matt is climbing a mountain when his elevation is higher than 1600 he has trouble breathing write an inequality that describes h the elevation at which breathing is difficult for Matt

Answers

Answer is   [tex]h > 1600[/tex]

The convention is to write the variable first on the left side, then the inequality sign, followed by the other side of the inequality.

Writing [tex]h > 1600[/tex] means that h is larger than 1600. Think of an alligator mouth that is represented by the "greater than sign". The mouth opens up to the larger side. In this case, h could be something like 1700 which is larger than 1600. So we'd say [tex]1700 > 1600[/tex] for instance.

solve the equation 2/3x-2=7

Answers

Answer: x = 27/2

Step-by-step explanation:

2/3x-2=7

2/3x=9

2/3x=27/3

2/3x(3/2)=27/3(3/2)

x=81/6

x=27/2

Answer: x = 27/2

Step-by-step explanation: In this equation, our first step is to isolate the x term by adding 2 to both sides.

On the left, -2 and +2 cancel out and were left

with 2/3x and on the right, 7 + 2 simplifies 9.

So we have 2/3x = 9.

In order to get x by itself, since it's being multiplied by a fraction,

we multiply both sides of the equation by the reciprocal of that fraction.

The reciprocal of a fraction is just that fraction

flipped so the reciprocal of 2/3 is 3/2.

So we have (3/2)(2/3x) = 9(3/2).

On the left, the 2's cancel and the 3's cancel.

On the right, 9(3/2) is 27/2.

So x = 27/2

Max and Sven bike away from home in the same direction starting at noon. They bike at constant speeds. Max bikes at xmph and he is ymph faster than Sven. By 4pm, how far ahead of Sven would Max be?

Answers

Answer:

Max would be 4y meters ahead by 4pm

Step-by-step explanation:

What we want to calculate here is the difference in the distance they have covered by 4pm given the speed at which they traveled.

Mathematically, distance = speed * time

The time is just the difference between 12 noon and 4pm which is 4 hours

Let’s tackle Max’s

He’s biking at x km/h, so the distance he would have covered by 4pm would be 4 * x = 4x meters

Now let’s tackle Sven

Sven is biking at a speed which is y mph less than Max’s x mph

Thus his speed would be (x-y) mph

His distance covered would be 4(x-y) meters

Now the difference between their bikes distance at 4pm would be;

4x - [4(x-y)]

= 4x -(4x -4y)

4x -4x + 4y

= 4y

Hence, Max would be 4y meters ahead by 4pm

What is the equation of the line that passes through the point (-6, 6) and has a
slope of
1/3?

Answers

Answer:

Using point-slope form we get:

y - 6 = 1/3(x + 6)

y - 6 = 1/3x + 2

y = 1/3x + 8

Plz help me the question is in the picture below

Answers

Answer:

function 2

Step-by-step explanation:

To do this you would already know that the first function's slope is 1 since r represents the x in slope intercept form. 2 will just be 1/1.1 since if you do y2-y1/x2-x2 you get 1/1.1 as the slope so function 2 will have a greater slope

The line’s graphed below are perpendicular. The slope of the red line is -1/3. What is the slope of the green line?

Answers

Answer:

C.  3

Step-by-step explanation:

Perpendicular lines have slopes that are negative inverses of the other.

This inverse of -1/3 is -3.  The negative of -3 is 3.

The slope of the perpendicular line is 3.

Other Questions
Joe and Danny have just won 350 arcade tickets. If each arcade game can be played with 12 tickets, how many will they have left over at the end of the day, if they play the maximum number of games? What category does the following comment fit best in? "The problem with the film is that it is difficult to get past the sloppy editing and amateurish cinematography." authenticity universality subject matter aesthetics The current taxonomic system that taxonomists use (and that we are using during our Summer session) follows a taxonomic scheme that recognizes _____ (a number) Kingdoms in the Domain Eukarya (also spelled Eucarya). Suppose you have a container filled with air at 212 oF. The volume of the container 1.00 L, the pressure of air is 1.00 atm. The molecular composition of air is 79% N2 and 21% O2 for simplification. Calculate the mass of air and moles of O2 in the container. When Windows deletes the driver package and driver files, in what situation might it not delete driver files used by the device that is being uninstalled? Which number is an irrational numbe? jasper owns a small retail store as a sole proprietor. the business records show that the cost of the stores inventory items has been steadily increasing. the cost of the end of the year inventory is 200,000 and the cost of the beginning of the year inventory was 250,000. jasper uses the fifo method of inventory valuation. Which of the following statements are true? a. jasper purchases more inventory during the year than sold during the same one year period. b. jasper would have a higher net income if he used the lifo method of inventory valuation instead of the fifo method c. jasper has apparently decreased the volume of items in his ending inventory as compared to the number of items in his beginning inventory d. since the cost of the stores inventory items is increasing, jasper will have a greater cost of goods sold figure under the fifo than the lifo. e. none of the above Convert the pressure 525.4 torr to kPa.Select one:O a. 70.0Ob. 3940O c. 9.90Od. 525 The outside of this set of four cubic blocks with no space between blocks is painted. What is the number of painted square faces? what is a good electric fan for your room? Why has the study of history changed over time?O A. Historians have stopped creating historical narratives and focusmore on presenting facts.O B. Historians have discovered new sources that change theirconclusions about past events.O C. Oral history has come to replace more formal written forms ofhistorical narrative.D. Archaeologists and anthropologists have come to dominate thediscipline of history. WILL MARK BRAINLIEST If Alan and Zack can clean a room in 30 minutes when working together, and Alan cleans twice as fast as Zack, how long would it take Alan to clean the room by himself? Which of the following is a true proportion of the figure based on the triangle proportionality theorem? Question 13 options: A) ab=ba B) cd=ab C) db=ac D) cb=ab how to solve for x?Knowledge and Understanding Draw the structure of 1,4-hexanediamine.Draw the molecule on the canvas by choosing buttons from the Tools (for bonds), Atoms, and Advanced TemplateTowbars. The single bond is active by default. Include all hydrogen atoms.View Available Hint(s) Since the 1900s, the study of communication has __________________________. Select one: a. expanded to reflect social and cultural changes in society. b. failed to address significant technical developments. c. focused primarily on public speaking. d. all of the above Draw the Lewis structure of acetaldehyde (CHCHO) and then choose the appropriate pair of molecular geometries of the two central atoms. a) tetrahedral/trigonal pyramidal.b) trigonal planar / linear.c) tetrahedral / trigonal planar.d) trigonal/tetrahedral.e) planar /trigonal planar. The following liquids are stored in a storage vessel at 1 atm and 25C. The vessels are vented with air. Determine whether the equilibrium vapor above the liquid will be flammable. The liquids are:________. a. Acetone b. Benzene c. Cyclohexane d. Toluene Problem The following present value factors are provided for use in this problem. 1 0.9259 0.9259 2 0.8573 1.7833 3 0.7938 2.5771 4 0.7350 3.3121 Cliff Co. wants to purchase a machine for $40,000, but needs to earn an 8% return. The expected year-end net cash flows are $12,000 in each of the first three years, and $16,000 in the fourth year. What is the machine's net present value? Please answer this correctly without making a mistake I need a correct answer