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?

2x + y = 8
-x - 3y = -12

3y + 12

-3y + 12

3y - 12

-3y - 12

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?

2x + y = 8
-x - 3y = -12

 3y + 12

 -3y + 12

 3y - 12

 -3y - 12

anonymous · Answer

i think the answer is -3y + 12. am i correct?

phoenixfire · Answer

That's correct.

anonymous · Answer

you're possitive? (:

phoenixfire · Answer

Yup.
-x=+3y-12
multiply each side by -1 to get a positive x
x=-3y+12
It has to be the answer.

anonymous · Answer

thats what i did! thank youu (: