Question

-4x + y =6
-5x - y = 21

explain????

Answer 1

well, Did you use a calculator If so then the answer is correct!!!! And -4x + y= 4 times X + Y. You figure out the rest.

Answer 2

-4x+y=6
-5x-y=21

You have to add the 2 equations so you get:

-9x=27
Divide both sides by -9 (so that you have x on the left side):

x=-3

Hope this helps :)