using substitution what are the answers to these equations x=-2y+3 and x=3y-7

Question

Hi,

Using substitution what are the answers for the following

 

x=-2y+3

x=3y-7

 

thank you

Answer 1

Since x = -2y+3 and x = 3y - 7 you can set the 2 expressions equal to each other like this:

-2y+3 = 3y - 7 and solve for y.

Add 2y to  each side:

3 = 5y - 7

Add 7 to each side:

10 = 5y

Divide both sides by 5:

2 = y.

Now that you know that y = 2, substitute the 2 back into either original equation:

x = -2(2)+3

x = -4+3

x = -1

The point where the systems cross is (-1, 2)