Jika 7x-y=6 dan 3x+2y=5 maka nilai x+y=

7x-y = 6     dikali -2
3x+2y = 5  dikali 1

-14x + 2y = -12
3x + 2y = 5
____________-
-17x = -17
x = 1

subtitusikan x

7x-y =6
7(1) – y =6
-y = 6-7
y = 1

x+y = 1+1 = 2