Mark is solving the following system.x+y+z=2 (1)
3x+2y+z=8 (2)
4x-y-7z=16 (3)

Step 1: He multiplies equation (1) by 7 and adds it to equation (3).
Step 2: He multiplies equation (3) by 2 and adds it to equation (2).

Which statement explains Mark’s mistake?
- He added equation (3) instead of equation (2) in step 1.
- He did not multiply equation (3) by the correct value.
- He did not eliminate the same variables in steps 1 and 2.
- He added equation (3) and equation (2) instead of subtracting.

Answers

Answer 1

Answer:

Solving the system of linear equations Mark tries to apply elementary transformations in order to eliminate one variable.

He makes such steps:

1. He multiplies equation (1) x+y+z=2 by 7 and adds it to equation (3) 4x-y-7z=16. This gives him:

7x+7y+7x+4x-y-7z=14+16,

11x+6y=30.

2. He multiplies equation (3) 4x-y-7z=16 by 2 and adds it to equation (2) 3x+2y+z=8. This step gives him:

8x-2y-14z+3x+2y+z=32+8,

11x-13z=40.

Thus, he did not eliminate the same variables in steps 1 and 2.

Answer: correct choice is C

Answer 2

Answer: I think its he didnt eliminate the same variables

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Find the Value of 8 1/3

Answers

The value of $8^{(1)/(3) }$ is 2.

What are the laws of exponents?

The Laws of Exponents are:

$x^(m) .x^(n) =x^(m+n)$

$(x^(m) )/(x^(n) ) =x^(m-n)$

$(x^{^(m))n}=x^(mn)$

$(xy)^(m) =x^(m) y^(m)$

According to the given question.

We have a number in exponential form $8^{(1)/(3) }$

The above exponential number can be written as

$8^{(1)/(3) }$

$= 2^{3((1)/(3) )}$ (because $2^(3) = 8$ )

$= 2$ ( because $(3)(1)/(3) = 1$ )

Hence, the value of $8^{(1)/(3) }$ is 2.

Find out more information about laws of exponents here:

brainly.com/question/568161

#SPJ2

$8^{ (1)/(3) } = \sqrt[3]{8} = 2$

$8^{ (2)/(3) } = \sqrt[3]{8^2} = \sqrt[3]{64} = 4$

7x+3y=22 4y=20 I need to know how to write this equation out with the answer

Answers

$\begin{cases} 7x+3y=22 \n 4y=20 \ \ /:4 \end{cases}\n \n\begin{cases} 7x+3 \cdot 5=22 \n y= 5 \end{cases}\n \n\begin{cases} 7x+15=22 \ \ |-15 \n 4y=20 \end{cases}$

$\begin{cases} 7x+15 -15=22 -15 \n y=5 \end{cases}\n \n\begin{cases} 7x =7\ \ / :7 \n y=5 \end{cases}\n \n\begin{cases} x =1 \n y=5 \end{cases}\n \n$

7x+3y=22
4y=20

4y=20
y=5

Substitute to first equation
7x+15=22
7x=7
x=1

State an equation, in vertex form for a quadratic relation whose vertex is not (0,0) but the vertex occurs the same location as x intercept

Answers

y= $(x-1)^(2)$

The vertex would be at (1,0). It also touches the x axis at (1,0).

NOTE I just edited the last sentence

Use the rules of multiplication by powers of 10 to calculate 20 times 100.

Answers

its 2000 becasue 200* 10 eqoals 2000

The answer is 2000 because 20 times 100 it equals 2000

Which of these is a simplified form of the equation 9p + 3 = − p + 7 + 2p + 3p?5p = 4

15p = 10

9 = 4

12 = 13

Answers

Answer:

Option (a) is correct.

5p = 4

Step-by-step explanation:

Given : equation 9p + 3 = − p + 7 + 2p + 3p

We have to simplify the given equation 9p + 3 = − p + 7 + 2p + 3p.

Consider the given equation 9p + 3 = − p + 7 + 2p + 3p

Like terms are terms having same variable with same power.

Adding like terms, we get,

9p + 3 = 7 + 4p

Subtract 4p both isde, we have,

9p - 4p + 3 = 7 + 4p -4p

Simplify, we get,

5p + 3 = 7

Subtratc 3 both isde, we have,

5p = 4

Thus, option (a) is correct.

Move all the p's to one side and the number to the other side: 9p + p - 2p - 3p = 7 - 3 5p = 4

5.2x - 1.7x = 7

what is the value of x?

Answers

5.2x - 1.7x = 73.5x = 7
x = 2

The answer is: x = 2.

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