Question

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

3x + y = 8
-x - 2y = -10
Answer
2y + 10
-2y - 10
-2y + 10
2y - 10

Answer 1

-x - 2y = -10
-x = -10 + 2y
x = 10 - 2y = -2y + 10

So -2y + 10

Answer 2

x=10-2y