Answer:
=12x+y
Step-by-step explanation:
Combine like terms
=5x+-3y+7x+4y
=(5x+7x)+(-3y+4y)
Answer: <u><em>A, because when x=1/-1 you don't need to write down the one meaning it is -x and then +2 is the y which means the full answer is y=-x+2</em></u>
Z = -2