Question

For the following system, if you isolated x in the first equation to use the Substitution Method, what expression would you substitute into the second equation?

−x + 2y = −6
3x + y = 8

Answer 1

First, we write the first equation where the left side contains x and y in the right side. We do as follows:

x = 2y + 6

You, then substitute the equation to the second one.

3(2y + 6) + y = 8
6y + 18 + y = 8
7y = -10
y = -10/7
x = 22/7