Sagot :
y = x - 7
2x + y = 8
2x + (x - 7) = 8
2x + x - 7 = 8
3x - 7 = 8
+ 7 + 7
3x = 15
3 3
x = 5
y = x - 7
y = 5 - 7
y = -2
(x, y) = (5, -2)
2x + y = 8
2x + (x - 7) = 8
2x + x - 7 = 8
3x - 7 = 8
+ 7 + 7
3x = 15
3 3
x = 5
y = x - 7
y = 5 - 7
y = -2
(x, y) = (5, -2)