1.x+y=4 dan 2x-y=3 2.2x+y=12 dan x+2y=9

Bab Sistem Persamaan Linear Dua Variabel

1. x + y = 4
y = 4 - x

2x - y = 3
2x - (4 - x) = 3
2x - 4 + x = 3
3x = 3 + 4
x = 7/3

y = 4 - x
y = 12/3 - 7/3
y = 5/3

2. 2x + y = 12
y = 12 - 2x

x + 2y = 9
x + 2(12 - 2x) = 9
x + 24 - 4x = 9
-3x = 9 - 24
x = -15/-3
x = 5

y = 12 - 2x
y = 12 - 2(5)
y = 12 - 10
y = 2