Please help with step by step.

Answer:

[tex]a \cdot b = 1[/tex]

Step-by-step explanation:

[tex] a = 5i + 7j [/tex]

[tex] b = -4i + 3j [/tex]

[tex] a = a_xi + a_yj [/tex]

[tex]b = b_xi + b_yj[/tex]

[tex] a \cdot b = a_xb_x + a_yb_y [/tex]

[tex] a \cdot b = (5)(-4) + (7)(3) [/tex]

[tex] a \cdot b = -20 + 21 [/tex]

[tex]a \cdot b = 1[/tex]

Answer:

[tex]\boxed{-20i^2 -13ij+21j^2}[/tex]

Step-by-step explanation:

[tex]\sf Plug \ in \ the \ values.[/tex]

[tex](5i+7j) \cdot (-4i+3j)[/tex]

[tex]\sf Expand \ brackets.[/tex]

[tex]5i(-4i+3j)+7j(-4i+3j)[/tex]

[tex]-20i^2 +15ij+-28ij +21j^2[/tex]

[tex]\sf Combine \ like \ terms.[/tex]

[tex]-20i^2 -13ij+21j^2[/tex]

Answer:

=6 units squared

Step-by-step explanation:

area=1/2h(a+b)

        =1/2×2(4+2)

        =6

Answer: [tex]\frac{4}{3}[/tex]

Step-by-step explanation:

This is a multiplication problem. You are multiplying [tex]\frac{1}{3}[/tex] by 4. This also means 4 divided by 3. They are both the same.

Answer:

396 in ^3

Step-by-step explanation:

The volume of a rectangular prism is

V = l*w*h  where l is the length, w is the width, and h is the height

V = 12 * 3 * 11

V = 396 in ^3

Answer:

[tex]\boxed{\boxed{ x=\frac{C-By}{A}; A\neq 0}}[/tex]

Step-by-step explanation:

[tex]Ax+By=C\\\\Ax+By-By=C-By\\\\Ax=C-By\\\\\frac{Ax=C-By}{A}\\\\\boxed{ x=\frac{C-By}{A}; A\neq 0}[/tex]

Hope this helps.

Answer:

[tex]x=2[/tex]

Step-by-step explanation:

[tex]\frac{3x-2}{7}-\frac{5x-8}{4}=\frac{1}{14}[/tex]

In order to factor an integer, we need to divide it by the ascending sequence of primes 2, 3, 5.

The number of times that each prime divides the original integer becomes its exponent in the final result.

In here,  Prime number 2 to the power of 2 equals 4.

[tex]\frac{3x-2}{7}-\frac{5x-8}{2^{2} }=\frac{1}{14}[/tex]

First, We need to add fractions-

Rule:-

[tex]\frac{A}{B} +\frac{C}{D} =\frac{\frac{LCD}{B}+\frac{LCD}{D}C }{LCD}[/tex]

LCD = [tex]7 \cdot 2^{2}[/tex]

[tex]\frac{4(3x-2)+7(-(5x-8))}{7*2^{2} } =\frac{1}{14}[/tex]

[tex]x=2[/tex]

OAmalOHopeO

The answer is 1/2 because there are total 10 questions. So, the probability of getting 5 correct answers is 5/10 that is 1/2.

Mark me as brainleist

Answer:

[tex]\boxed{\sf \bf \ \ -2i(6-7i)=-14-12i \ \ }[/tex]

Step-by-step explanation:

Hello, please consider the following.

[tex]-2i(6-7i)=-12i+14i^2=-14-12i[/tex]

Hope this helps.

Do not hesitate if you need further explanation.

Thank you

Answer:

A

Step-by-step explanation:

Answer = A

Answer:

$179.80

Step-by-step explanation:

799-79.80=719. That's the down payment subtracted from the total price of the refrigerator. 719/4, since there's four equal installments, gives you 179.8. Since cents go in 10s, you make it 179.80 and slap a dollar sign in front of that.

Answer:

  log(1/10) = -1

Step-by-step explanation:

Use the law of exponents and the meaning of logarithm.

  1/10 = 10^-1

  log(10^x) = x

So, you have ...

  log(1/10) = log(10^-1)

  log(1/10) = -1

Answer:

Step-by-step explanation:

Given the limit of a function [tex]\lim_{h \to 0} \frac{(1+h)-1}{h}[/tex], to evaluate the limit, the following steps must be taken.

Step 1: Substitute h = 0 into the function given.

[tex]= \lim_{h \to 0} \frac{(1+h)-1}{h}\\\\[/tex]

[tex]= \frac{(1+0)-1}{0}\\\\= \frac{1-1}{0} \\\\= \frac{0}{0} (indeterminate)\\[/tex]

Step 2: Apply l'hospital rule

[tex]\lim_{h \to 0} \frac{\frac{d}{dh}[(1+h)-1] } {\frac{d}{dh}(h) } \\\\= \frac{0+1-0}{1}\\ \\= \frac{1}{1} \\ \\= 1[/tex]

Hence the limit of the function [tex]\lim_{h \to 0} \frac{(1+h)-1}{h} \ is \ 1[/tex]

Answer:

The answer is option B

Step-by-step explanation:

To find the coefficient of the third term in

[tex](x + 5)^{7} [/tex]

Rewrite the expansion in the form

[tex](a + x)^{n} [/tex]

where n is the index

So we have

[tex] ({5 + x})^{7} [/tex]

After that we use the formula

[tex]nCr( {a}^{n - r} ) {x}^{r} [/tex]

where r is the term we are looking for

For the third term we are looking for the term containing x²

that's

r + 1 = 3

r = 2

So to find the coefficient of the third term

We have

[tex]7C2[/tex]

Hope this helps you

first of all, the notation is wrong it should be [tex] {}^nC_r \text{ and more usual notation is } {n \choose k} [/tex]

second, the

[tex](r+1)^{\text{th}} \text{ term } T_{r+1} \text{ in the expansion of } (x+a)^n \text{ is } {n \choose r}x^{(n-r)}a^r[/tex]

here [tex] a=5 \text{ and } n=7 \text{ and for } 3^{\text{rd}} \text{ term } T_3, \quad r+1=3 \implies r=2 [/tex]

so the coefficient of third term is, [tex]{7 \choose 2}={7\choose 5}[/tex]

an important property of binomial coefficient you should know:

[tex] {n \choose k}={n \choose {n-k}}[/tex]

and if you interchange [tex] x \text{ and } a[/tex]

only the "order" will get reversed. i.e. the series will start from back.

another thing, the [tex] k^{\text{th}} \text{ term from beginning, is the } (n-k+2)^{\text{th}} \text{ term from behind}[/tex]

Step-by-step explanation:

the box is

9 in × 3.5 in × 4.5 in = 141.75 in³

each block is

0.5 in × 0.5 in × 0.5 in = 0.125 in³ (1/8 in³)

so, we can fit

141.75 / 0.125 = 1134

blocks into the box.

and they fit neatly, as the dimensions of the box and the cubes allow a tight packing without any empty left over space in the box.

Answer:

26. 35

27. 65

28. 13

Step-by-step explanation:

26. The big angle POR is given as 59 and the smaller angle inside it (POQ) is given as 24. Since the angles POQ and QOR add up to the angle POR,

QOR = POR - POQ    |     59-24 = 35

27. We are given the angles of all the smaller angles in the large angle POS. POQ, QOR and ROS are 19, 31 and 15 respectively. Since all of them add up to create the angle POS, POS = 19+31+15 = 65

28. We can use the second and third given angles (POR and POQ) to find the QOR which we can then use to find ROS. This first step is very similar to 26. We are given POR as 61 and POQ as 28, therefore QOR = 61-28 = 33

Since we now know QOR and QOS, we can repeat the process and deduct that because the two smaller angles add up to the bigger one (QOS), we can find ROS by subtracting QOR (from above) from the given QOS (46):

46 - 33 = 13

Hope this helped!

Answer:

Goes on forever.

Step-by-step explanation:

Answer:

  0.4 meters

Step-by-step explanation:

The volume is ...

  V = LHB

  12.8 m³ = (8(5B))(5B)(B) = 200B³ . . . fill in given values

  0.064 m³ = B³ . . . . . simplify

  ∛0.064 m = B = 0.4 m

The breadth of the wall is 0.4 meters.

Answer:

The  confidence interval is  [tex]0.304 < p < 0.324[/tex]

Step-by-step explanation:

From the question we are told

      The sample proportion [tex]\r p = 0.314[/tex]

      The margin of error  is [tex]E = 0.01[/tex]

The confidence interval for  p is mathematically represented as

       [tex]\r p - E < p < \r p + E[/tex]

=>    [tex]0.314 - 0.01 < p < 0.314 + 0.01[/tex]

=>   [tex]0.304 < p < 0.324[/tex]

Answer:

5/2

Step-by-step explanation:

5^(-3). 2^2.5^6 / (2^3.5^2)

By the law of indices,

=5^(-3+6-2).2^(2-3)

=5^1.2^(-1)

=5. 2^-1

=5/2

Answer:

5+4 = 9

6+4 = 10

7+4 =11

Step-by-step explanation:

Answer:

(5,9)

(6,10)

(7,11)

Step-by-step explanation:

w = m + 4

when m = 5,

w = 5 + 4 = 9

when m = 6

w = 6 + 4 = 10

when m = 7

w = 7 + 4 = 11

Answer:

3

Step-by-step explanation:

z - 2x

--------

y

Let x = 3  y = -4 and z  =-6

-6 - 2(3)

--------

-4

-6 -6

---------

-4

-12

-----

-4

3

Answer:

3

Step-by-step explanation:

To solve this, we need to plug in each of the numbers to the equation.

x = 3, y = - 4, z = - 6

[tex]\frac{z-2x}{y} = \frac{-6-2(3)}{-4}[/tex]

Let's solve the parenthesis first. - 2 * 3 = - 6.

[tex]\frac{-6-6}{-4}[/tex]

We then subtract -6 - 6.

[tex]\frac{-12}{-4}[/tex]

Then, we divide (cancel out the negatives).

[tex]-12 / -4 =3[/tex]

Our final answer is 3. Hope this helps!

Answer:

Our three numbers are 8, 48, and 16.

Step-by-step explanation:

Let the first, second, and third numbers be x, y, and z, respectively.

The sum of them is 72. In other words:

[tex]x + y + z = 72[/tex]

The second number y is three times the third number z. So:

[tex]y = 3z[/tex]

And the third number z is eight more than the first number x. So:

[tex]z = x + 8[/tex]

To find the numbers, solve for the system. We can substitute the last two equations into the first:

[tex]x + (3z) + ( x + 8) = 72[/tex]

Substitute again:

[tex]\displaystyle x + 3(x+8) + x+8 = 72[/tex]

Solve for x. Distribute:

[tex]x+3x+24+x+8=72[/tex]

Combine like term:

[tex]5x + 32 = 72[/tex]

Subtract:

[tex]5x = 40[/tex]

And divide:

[tex]x=8[/tex]

Thus, the first number is eight.

And since the third number is eight more than the first, the third number z is 16.

The second number is three times the third. Thus, the second number y is 3(16) or 48.

Our three numbers are 8, 48, and 16.

Answer:

Lori will pay $12 more if she makes monthly payments

Step-by-step explanation:

to find how much she will pay for 6 months, we have to multiply 12 by 6 to get $72

subtracting the amount she would pay as a down payment

$72 - $60 is $12

Lori will pay $12 more if she makes monthly payments

Answer:

X 1 for Y 4

X 5 for Y 8

X 2 for Y 5

Step-by-step explanation:

We can substitute the values of Y in the formula and then subtract three from both sides.

Answer:

Yes, they make sense outside the context of temperature.

Step-by-step explanation:

If you are standing in a line, and mark your current position as 0 then if you take two steps ahead it can be counted as positive and if you take two steps back from your current position it can be counted as negative. The positive and negative can denote your forward and backward movement respectively.

If we denote the growth in companies revenue as positive and dip as negative then it would also make sense. A positive number would mean profit for the company while a negative sign would show loss.

Answer:

y > -1

Step-by-step explanation:

the line is going across the y axis and is everything above -1

Answer: 2.08 km

Step-by-step explanation:

Side of Square = 520 m

Perimeter of Square = Side × 4

                                  = 520 × 4

                                  = 2080 m

1000 m = 1km

2080 m = 2080 ÷ 1000

              = 2.08 km

Answer:

(x+3)^2=-4(y-3)

Step-by-step explanation:

(x-h)^2 = 4p(y-k)

P is the distance between the focus and vertex

P = 1 --> used distance formula for the points of -3,2 -3,3

Vertex is -3,3 --> according to picture

(x+3)^2=-4(y-3)

P is negative since it goes downwards in the picture.