Question

Carolyn was asked to solve the following system of equations. Her work is shown.

What error did Carolyn make? Identify her mistake and explain the error.


1. Carolyn did not subtract 4 from both sides of the equation.

2. Carolyn did not distribute the -2 to both terms

3. Carolyn did not substitute x + 2 for y

4. Carolyn did not substitute 3 for x to find the value of y for the solution

Answer 1

Answer:

Carolyn did not distribute the -2 to both terms

Step-by-step explanation:

This was how Carolyn solved the second step:

$3x-2(x+2)=7\\3x-2x+4=7$

She did multiply both terms in the parentheses by 2, but she did not change the sign for the 4. It should instead be -4 since a negative number multiplied by a positive number will always make a negative number.

Here is the correct way of solving it:

$3x-2(x+2)=7\\3x-2x-4=7$

I hope this helps!