Answer:
Explanation:
in this case, we already know that x= -10 so we can substitute in the other problem, -10x9 = -90 so now we can get rid of that by adding + 90 on each side making it 9y=81 by this time, we see that both sides are divisable by 9 divide both by nine and you get: 1y=9 from that you can finally answer the question with
x= -10 y= 9