Question

For the following system, use the second equation to make a substitution for y in the first equation. 2x + y = 5 y + 3 = 2x

Answer 1

For the second equation, y=2x-3. Substituting this in, you get 2x+2x-3=5. Add the 2x's (4x), and add 3 to the 5 (8). You should get 4x=8, which will give you x=2.  

Answer 2

If y equals 2x - 3 in the second equation, than subsitute it in for y in the first.
2x + 2x - 3 = 5
4x - 3 = 5
4x = 8
x=2
2(2) + y = 5
x = 2 and y = 1