-7x-y=-5 x-5y=11} x, y?

Bab Persamaan Linear
Matematika SMP Kelas VIII

-7x - y = -5
y = -7x + 5

x - 5y = 11
x - 5 (-7x + 5) = 11
x + 35x - 25 = 11
36x = 25 + 11
x = 36/36
x = 1

y = -7x + 5
   = -7 . 1 + 5
   = -2

jadi, x = 1 dan y = -2