Answer:
(f • g) (x) = 2x² + 9x + 7Step-by-step explanation:
f(x) = 2x² + x - 3
g(x) = x + 2
To find (f • g) (x) substitute g(x) into every x in f (x)
That's
(f • g) (x) = 2(x + 2)² + x + 2 - 3
Expand and simplify
(f • g) (x) = 2( x² + 4x + 4) + x - 1
= 2x² + 8x + 8 + x - 1
Group like terms
= 2x² + 8x + x + 8 - 1
We have the final answer as
(f • g) (x) = 2x² + 9x + 7Hope this helps you
Rewrite the equation by completing the squares x^2-x-20
Answer: x = ¹/₂ ± √⁸¹
------------
2
Step-by-step explanation:
First write out the equation
x² - x - 20
Now we now write the equation by equating to 0
x² - x - 20 = 0
We now move 20 to the other side of the equation. So
x² - x = 20,
We now add to both side of the equation square of the half the coefficient of the (x) and not (x²) which is (1) . So, the equation now becomes
x² - x + ( ¹/₂ )² = 20 + ( ¹/₂ )²
x² - ( ¹/₂ )² = 20 + ¹/₄
( x - ¹/₂ )² = 20 + ¹/₄, we now resolve the right hand side expression into fraction
( x - ¹/₂ )² = ⁸¹/₄ when the LCM is made 4
Taking the square root of both side to remove the square,we now have
x - ¹/₂ = √⁸¹/₄
x - ¹/₂ = √⁸¹/₂
Therefore,
x = ¹/₂ ± √⁸¹
-----------
2
6th grade math, help me please.
Answer:
B Kim rode 3 more miles per week than Eric rode.
help me plz I really dont get it
Complete the point-slope equation of the line through (3,-8) (6,-4)
Answer:
y + 4 = 4/3(x - 6).
Step-by-step explanation:
The point-slope formula is shown below. We just need to find the slope.
(-4 - (-8)) / (6 - 3) = (-4 + 8) / 3 = 4 / 3
m = 4/3, y1 = -4, and x1 = 6.
y - (-4) = 4/3(x - 6)
y + 4 = 4/3(x - 6).
Hope this helps!
The mean number of words per minute (WPM) typed by a speed typist is 149149 with a standard deviation of 1414 WPM. What is the probability that the sample mean would be greater than 147.8147.8 WPM if 8888 speed typists are randomly selected
Answer:
The probability is [tex]P(\= X > x ) = 0.78814[/tex]
Step-by-step explanation:
From the question we are given that
The population mean is [tex]\mu = 149[/tex]
The standard deviation is [tex]\sigma = 14[/tex]
The random number [tex]x = 147.81[/tex]
The sample size is [tex]n = 88[/tex]
The probability that the sample mean would be greater than [tex]P(\= X > x ) = P( \frac{ \= x - \mu }{\sigma_{\= x} } > \frac{ x - \mu }{\sigma_{\= x} } )[/tex]
Generally the z- score of this normal distribution is mathematically represented as
[tex]Z = \frac{ \= x - \mu }{\sigma_{\= x} }[/tex]
Now
[tex]\sigma_{\= x } = \frac{\sigma }{\sqrt{n} }[/tex]
substituting values
[tex]\sigma_{\= x } = \frac{14 }{\sqrt{88} }[/tex]
[tex]\sigma_{\= x } = 1.492[/tex]
Which implies that
[tex]P(\= X > x ) = P( Z > \frac{ 147.81 - 149 }{ 1.492} )[/tex]
[tex]P(\= X > x ) = P( Z > -0.80 )[/tex]
Now from the z-table the probability is found to be
[tex]P(\= X > x ) = 0.78814[/tex]
Which linear inequality is represented by the graph?
Answer:
A. y ≤ 1/2x + 2
Step-by-step explanation:
Well look at the graph,
It is a solid line with it shaded down,
meaning it is y ≤,
So we can cross out B. and D.
So the y intercept is 2, we know this because the y intercept is the point on the line that touches the y axis.
now the slope can be found by seeing how far away each points are from each other,
Hence, the answer is A. y ≤ 1/2x + 2
The average score of 100 students taking a statistics final was 70 with a standard deviation of 7. Assuming a normal distribution, what is the probability that a student scored greater than 65
Answer:
50
Step-by-step explanation:
50 because of the 100 of 79 to 7
McKenzie has a bag contains six red marbles four blue marbles and 14 yellow marbles if she chooses one marble from the bag what is the probability that the marble is not yellow
Answer:
5/12
Step-by-step explanation:
Total number of marbles in the bag
6red+ 4blue + 14 yellow = 24 marbles
Not yellow marbles = 10 marbles
P ( not yellow ) = number of not yellow marbles / total marbles
=10/24
= 5/12
Answer:
5/12
Step-by-step explanation:
6 red marbles
4 blue marbles
14 yellow marbles
total marbles = 6 + 4 + 14 = 24 marbles
24 - 14 = 10 marbles
10 marbles are not yellow.
P(not yellow) = 10/24 = 5/12
Rafael made 20,000 in taxable income last year. Suppose the income tax rate is 15% for the first 8000 plus 17% for the amount over 8000. How much must Rafael pay in income tax for the last year?
The answer is 3,240
Explanation:
To calculate the total income tax, it is necessary to calculate what is the 15% of 8000, and 17% for the remaining money, which is 12.000 (20,000 - 8,000= 12,000). Considering the statement specifies the 15% is paid for the first 8,000 and from this, the 17% is paid. Now to know the percentages you can use a simple rule of three, by considering 8000 and 12000 as the 100%. The process is shown below:
1. Write the values
[tex]8000 = 100[/tex]
[tex]x = 15[/tex] (the percentage you want to know)
2. Use cross multiplication
[tex]x =\frac{8000 x 15 }{100}[/tex]
[tex]x = 1200[/tex]
This means for the first 8000 the money Rafael needs to pay is 1,200
Now, let's repeat the process for the remaining money (12,000)
[tex]12000 = 100\\\\[/tex]
[tex]x = 17[/tex]
[tex]x = \frac{12000 x 17}{100}[/tex]
[tex]x = 2040[/tex]
Finally, add the two values [tex]1200 + 2040 = 3240[/tex]
Find the centroid of the quarter of the unit circle lying in the fourth quadrant.
Step-by-step explanation:
In the fourth quadrant, the equation of the unit circle is:
y = -√(1 − x²), 0 ≤ x ≤ 1
The x and y coordinates of the centroid are:
cₓ = (∫ x dA) / A = (∫ xy dx) / A
cᵧ = (∫ y dA) / A = (∫ ½ y² dx) / A
For a quarter circle in the fourth quadrant, A = -π/4.
Solving each integral:
∫₀¹ xy dx
= ∫₀¹ -x √(1 − x²) dx
= ½ ∫₀¹ -2x √(1 − x²) dx
If u = 1 − x², then du = -2x dx.
When x = 0, u = 1. When x = 1, u = 0.
= ½ ∫₁⁰ √u du
= ½ ∫₁⁰ u^½ du
= ½ (⅔ u^³/₂) |₁⁰
= (⅓ u√u) |₁⁰
= 0 − ⅓
= -⅓
∫₀¹ ½ y² dx
= ½ ∫₀¹ (1 − x²) dx
= ½ (x − ⅓ x³) |₀¹
= ½ [(1 − ⅓) − (0 − 0)]
= ⅓
Therefore, the x and y coordinates of the centroid are:
cₓ = (-⅓) / (-π/4) = 4/(3π)
cᵧ = (⅓) / (-π/4) = -4/(3π)
The pressure applied to a leverage bar varies inversely as the distance from the object. If 150 pounds is required for a distance of 10 inches from the object how much pressure is needed for a distance of 3 inches
Answer:
500 pounds
Step-by-step explanation:
Let the pressure applied to the leverage bar be represented by p
Let the distance from the object be represented by d.
The pressure applied to a leverage bar varies inversely as the distance from the object.
Written mathematically, we have:
[tex]p \propto \dfrac{1}{d}[/tex]
Introducing the constant of proportionality
[tex]p = \dfrac{k}{d}[/tex]
If 150 pounds is required for a distance of 10 inches from the object
p=150 poundsd=10 inches[tex]150 = \dfrac{k}{10}\\\\k=1500[/tex]
Therefore, the relationship between p and d is:
[tex]p = \dfrac{1500}{d}[/tex]
When d=3 Inches
[tex]p = \dfrac{1500}{3}\\\implies p=500$ pounds[/tex]
The pressure applied when the distance is 3 inches is 500 pounds.
Perform the indicated operation and write the result in standard form: (-3+2i)(-3-7i)
A. -5+27i
B. 23+15i
C. -5+15i
D. 23-15i
E-5-27I
Answer:
23+15i
Step-by-step explanation:
(-3+2i) (-3-7i)
multiply -3 w (-3+2i) and multiply -7i w (-3+2i)
9-6i+21i-14i^2
combine like terms
9+15i-14i^2
i squared is equal to -1 so
9+15i-(14x-1)
9+14+15i
23+15i
hope this helps :)
Simplify the polynomial, then evaluate for x=3 x^2+2x-3-2x^2+x+4
Answer:
The answer is
19Step-by-step explanation:
x² + 2x - 3 - 2x² + x + 4
Group like terms
That's
x² - 2x² + 2x + x - 3 + 4
Simplify
- x² + 3x + 1
when x = 3
We have
(-3)² + 3(3) + 1
9 + 9 + 1
18 + 1
19
Hope this helps you
Katie wants to create a rectangular frame for a picture. She has 60 inches of material. If she wants the length to be 3 more than 2 times the width what is the largest possible length
Answer:
Largest possible length is 21 inches.
Step-by-step explanation:
Given:
Total material available = 60 inches
Length to be 3 more than twice of width.
To find:
Largest possible length = ?
Solution:
As it is rectangular shaped frame.
Let length = [tex]l[/tex] inches and
Width = [tex]w[/tex] inches
As per given condition:
[tex]l = 2w+3[/tex] ..... (1)
Total frame available = 60 inches.
i.e. it will be the perimeter of the rectangle.
Formula for perimeter of rectangle is given as:
[tex]P = 2 \times (Width + Length)[/tex]
Putting the given values and conditions as per equation (1):
[tex]60 = 2 \times (w+ l)\\\Rightarrow 60 = 2 \times (w+ 2w+3)\\\Rightarrow 60 = 2 \times (3w+3)\\\Rightarrow 30 = 3w+3\\\Rightarrow 3w = 27\\\Rightarrow w = 9 \ inch[/tex]
Putting in equation (1):
[tex]l = 2\times 9+3\\\Rightarrow l = 21\ inch[/tex]
So, the answer is:
Largest possible length is 21 inches.
A painter takes hours to paint a wall. How many hours will the painter take to paint 8 walls if she works at the same rate?
Answer:
20.8 hours
Step-by-step explanation:
2 3/5 = 2.6.The painter will take (2.6 × 8) = 20.8 hours to paint a wall.
Hope this helps and pls mark as brianliest :)
Answer:
20.8, 20 4/5, and 104/5
What is the inverse of the function below?
f(x) = x-5
A. f^-1(x) = x + 5
B. f^-1(X) = x-5
C. f^-1(x) = -x + 5
D. f^-1(x) = -x-5
Answer:
f^-1(x) = x + 5
Step-by-step explanation:
f(x) = x-5
y = x-5
Exchange x and y
x = y-5
Solve for y
x+5 = y-5+5
x+5 =y
The inverse is x+5
Part of the proceeds from a garage sale was $440 worth of $10 and $20 bills. If there were 2 more $10 bills than $20 bills, find the number of each denomination.
Hey there! I'm happy to help!
Let's set this up a system of equations where x represents the number of 10 dollar bills and y represents the number of 20 dollar bills.
10x+20y=440
x=y+2
We see that x has a value of y+2, so we can replace the x in the first equation with y+2 so we can solve for y.
10(y+2)+20y=440
We use distributive property to undo the parentheses.
10y+20+20y=440
We combine like terms.
30y+20=440
We subtract 20 from both sides.
30y=420
y=14
Since there are 2 more $10 bills, there would be 16 of those.
Therefore, there are 16 $10 bills and 14 $20 bills.
Have a wonderful day! :D
What is the value of s in the equation 3 r equals 10 plus 5 s, when r equals 10? 4 8 100 200
Answer
4Step-by-step explanation:
Given,
r = 10
Let's create an equation,
[tex]3r = 10 + 5s[/tex]
plugging the value of r
[tex]3 \times 10 = 10 + 5s[/tex]
Multiply the numbers
[tex]30 = 10 + 5s[/tex]
Move 5s to L.H.S and change its sign
Similarly, Move 30 to R.H.S and change its sign.
[tex] - 5s = 10 - 30[/tex]
Calculate
[tex] - 5s = - 20[/tex]
The difference sign ( - ) should be cancelled on both sides
[tex]5s = 20[/tex]
Divide both sides of the equation by 5
[tex] \frac{5s}{2} = \frac{20}{5} [/tex]
Calculate
[tex]s = 4[/tex]
The value of s is 4.
Hope this helps..
Best regards!!
Answer:
A. 4 (on edgenuity)
Step-by-step explanation:
What is viscosity?
O A measure of the oil's quality
O An oil's resistance to flow at different temperatures
A reference to synthetic oil; all oils with viscosity are synthetic
O A new motor oil ingredient
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Answer:
viscosity is the state of being thick, sticky, and semifluid in consistency, due to internal friction.
"cooling the fluid raises its viscosity"
a quantity expressing the magnitude of internal friction, as measured by the force per unit area resisting a flow in which parallel layers unit distance apart have unit speed relative to one another.
plural noun: viscosities
"silicone oils can be obtained with different viscosities"
Step-by-step explanation:
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. hope this helps you :)
Answer:
O An oil's resistance to flow at different temperatures
Step-by-step explanation:
Internal friction of a moving fluid .
If 2/3 of a certain number is subtracted from twice the number, the result is 20. Find the number.
Answer:
[tex]\boxed{x = 15}[/tex]
Step-by-step explanation:
Let the number be x
Condition:
[tex]2x - \frac{2}{3} x = 20[/tex]
Multiplying 3 to both sides
=> 3(2x) - 2x = 3(20)
=> 6x - 2x = 60
=> 4x = 60
Dividing both sides by 4
=> x = 15
Answer:
15
Step-by-step explanation:
Let x be that number.
2/3 of x subtracted from twice of x is 20.
2x - 2/3x = 20
Solve for x.
Combine like terms.
4/3x = 20
Multiply both sides by 3/4
x = 60/4
x = 15
The number is 15.
Write your answer as a whole number or a mixed number in simplest form. Include the correct unit in your answer
Answer:
15 pt
Step-by-step explanation:
to convert qt to pt you multiply by 2 so 7 and 1/2 times 2 is 15
The grade point average collected from a random sample of 150 students. Assume that the population standard deviation is 0.78. Find the margin of error if cequals0.98.
Answer:
15%
Step-by-step explanation:
To calculate the margin of error, we can adopt this formula
Margin of error = critical value* (standard deviation/sqrt of sample size)
Where critical value is 2.33, sd is 0.78 and sample size is150.
Thus, we have:
Margin of error = 2.33*(0.78/√150)
Margin of error = 2.33*(0.78/12.2474)
Margin of error =2.33*0.06369
Margin of error = 0.1484 which is a 15% margin of error
find the arithmetic
mean median and mode
Step-by-step explanation:
The formulae to find them are:
arithmetic mean in individual series = sum x/Narithmetic mean in discrete data= sum fx/Narithmetic mean in continuous data= sum fm/N[tex]median = \frac{n + 1}{2} th[/tex]and mode= number of greatest frequency.
(note; f is frequency, N is number of data and x is x is the raw data)
hope it helps..
A sample of 26 offshore oil workers took part in a simulated escape exercise, resulting in the accompanying data on time (sec) to complete the escape.
389 357 359 364 375 424 326 395 402 373
374 371 365 367 365 326 339 393 392 369
374 359 357 403 335 397
A normal probability plot of the n 26 observations on escape time given above shows a substantial linear pattern; the sample mean and sample standard deviation are 371.08 and 24.45, respectively. (Round your answers to two decimal places.)
Required:
a. Calculate an upper confidence bound for population mean escape time using a confidence level of 95%.
b. Calculate an upper prediction bound for the escape time of a single additional worker using a prediction level of 95%.
Answer:
The upper confidence bound for population mean escape time is: 379.27
The upper prediction bound for the escape time of a single additional worker is 413.64
Step-by-step explanation:
Given that :
sample size n = 26
sample mean [tex]\bar x[/tex] = 371.08
standard deviation [tex]\sigma[/tex] = 24.45
The objective is to calculate an upper confidence bound for population mean escape time using a confidence level of 95%
We need to determine the standard error of these given data first;
So,
Standard Error S.E = [tex]\dfrac{\sigma }{\sqrt{n}}[/tex]
Standard Error S.E = [tex]\dfrac{24.45 }{\sqrt{26}}[/tex]
Standard Error S.E = [tex]\dfrac{24.45 }{4.898979486}[/tex]
Standard Error S.E = 4.7950
However;
Degree of freedom df= n - 1
Degree of freedom df= 26 - 1
Degree of freedom df= 25
At confidence level of 95% and Degree of freedom df of 25 ;
t-value = 1.7080
Similarly;
The Margin of error = t-value × S.E
The Margin of error = 1.7080 × 4.7950
The Margin of error = 8.18986
The upper confidence bound for population mean escape time is = Sample Mean + Margin of Error
The upper confidence bound for population mean escape time is = 371.08 + 8.18986
The upper confidence bound for population mean escape time is = 379.26986 [tex]\approx[/tex] 379.27
The upper confidence bound for population mean escape time is: 379.27
b. Calculate an upper prediction bound for the escape time of a single additional worker using a prediction level of 95%.
The standard error of the mean = [tex]\sigma \times \sqrt{1+ \dfrac{1}{n}}[/tex]
The standard error of the mean = [tex]24.45 \times \sqrt{1+ \dfrac{1}{26}}[/tex]
The standard error of the mean = [tex]24.45 \times \sqrt{1+0.03846153846}[/tex]
The standard error of the mean = [tex]24.45 \times \sqrt{1.03846153846}[/tex]
The standard error of the mean = [tex]24.45 \times 1.019049331[/tex]
The standard error of the mean = 24.91575614
Recall that : At confidence level of 95% and Degree of freedom df of 25 ;
t-value = 1.7080
∴
The Margin of error = t-value × S.E
The Margin of error = 1.7080 × 24.91575614
The Margin of error = 42.55611149
The upper prediction bound for the escape time of a single additional worker is calculate by the addition of
Sample Mean + Margin of Error
= 371.08 + 42.55611149
= 413.6361115
[tex]\approx[/tex] 413.64
The upper prediction bound for the escape time of a single additional worker is 413.64
Tessellations that use more than one one type of regular polygon are called regular tessellations?
Answer:
False
Step-by-step explanation:
A tessellation refest to a shape that is repeated over and over again covering a plane without any gaps or overlaps. The statement is false given that regular tessellations use only one polygon. Semi-regular tessellations are created with more than one type of regular polygon.
What is the measure of XYZ, given that yz and xy are tangent to ?
A.
212
B.
127
C.
106
D.
53
Answer:
D) 53 Degrees.
Step-by-step explanation:
Things we need to establish beforehand: We know that Lines OZ and OX are equal because they are both radii of the circle. We can make an Iscoceles traingle by drawing a line between ZX. We know angle YZO and angle YXO is a right angle because YZ and XY are tangent to the circle. The Arc angle is the same angle as angle ZOX.
1) Find angles OZX and OXZ. these will be 26.5, because 180-127 is 53, which is the sum of the two angles. the two angles are the same, so divide 53 by 2.
2) Find Angles XZY and ZXY. We know that YZO is a right angle, and both XZY and OZX make up this right angle so XZY + OZX = 90. OZX is 26.5, so 90-26.5=XZY. XZY = ZXY, so both angles equal 63.5.
3) Now that we have two angles of triangle XYZ, we can find angle XYZ. 180-(XZY+ZXY)=XYZ, so (180-(63.5+63.5)=53. Angle XYZ=53.
At time, t=0, Billy puts 625 into an account paying 6% simple interest. At the end of year 2, George puts 400 into an account paying interest at a force of interest, δt=16+t for t≥2. If both accounts continue to earn interest indefinitely at the levels given above, the amounts in both accounts will be equal at the end of year n. Calculate n.
Answer:
26
Step-by-step explanation:
Given that:
At time, t=0, Billy puts 625 into an account paying 6% simple interest
At the end of year 2, George puts 400 into an account paying interest at a force of interest, 1/(6+t), for all t ≥ 2.
If both accounts continue to earn interest indefinitely at the levels given above, the amounts in both accounts will be equal at the end of year n. Calculate n.
In order to calculate n;
Let K constant to be the value of time for both accounts
At time, t=0, the value of time K when Billy puts 625 into an account paying 6% simple interest is:
[tex]K = 625 \times (1+ 0.06 K)[/tex]
[tex]K = 625 +37.5 K[/tex]
At year end 2; George amount of 400 will grow at a force interest, then the value of [tex]K = 400 \times e^{\int\limits^2_k {\dfrac{1}{6+t}} \, dx }[/tex]
[tex]K =400 \times \dfrac{6+K}{6+2}[/tex]
[tex]K =400 \times \dfrac{6+K}{8}[/tex]
[tex]K =50 \times ({6+K})[/tex]
[tex]K =300+50K[/tex]
Therefore:
If K = K
Then:
625 + 37.5 = 300 +50 K
625-300 = 50 K - 37.5 K
325 = 12.5K
K = 325/12.5
K = 26
the amounts in both accounts at the end of year n = K = 26
It takes an older pump 3 times as long to drain a certain pool as it does a newer pump. Working together, it takes the two pumps 3 hours to
drain the pool. How long will it take the older pump to drain the pool working alone?
Do not do any rounding.
Answer:
it takes approximately 3 hours
Step-by-step explanation:
The difference between seven times a number and 9 is equal to three times the sum of the number and 2. Find the number
If x represents the number, which equation is correct for solving this problem?
The difference between seven times a number and 9 is equal to three times the sum of the number and 2. Find the number
If x represents the number, which equation is correct for solving this problem?
Answer:
Number:3.75
Equation:7 x-9=3(x+2)
Step-by-step explanation:
Let the number be x.
According to the question,
7 x-9=3(x+2)
7 x-9= 3 x+ 6
7 x- 3 x= 9+6
4 x= 15
x=15/4
x=3.75
If you verify the answer you will get,
11.25=11.25
Thank you!
Find the slope and y-intercept of the equation. y= 2/3x + 1
A. 2/3; 1
B. 1; 2/3
C. 2/3; -1
Answer:
The answer is A.
Step-by-step explanation:
In a linear equation, y = mx + b, m is represented as gradient (slope) and b is the y-intercept.
So for this question, m is 2/3 and b is 1.