The difference of x and two times y is 6. x - 2y = 6
From there I subtracted the bottom equation from the top equation, so it would look like: (x + y) - (x - 2y) = (12) - (6) x + y - x + 2y = 6 3y = 6 y = 2
from there you could plug in y as 2 in any equation above. I will use the top equation here. x + y = 12 x + (2) = 12 x = 10