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 = 9
4x + 5y = 9

−9 + 2y

−9 − 2y

9 − 2y

9 + 2y

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 = 9
4x + 5y = 9

 −9 + 2y

 −9 − 2y

 9 − 2y

 9 + 2y

anonymous · Answer

K so we're trying to get x isolated in the first equation. First, we subtract 2x to both sides and then divide by -1. That gives us x=2y-9, which is the same as your first answer.