Jika x dan y memenuhi sistem persamaan 5x - 3y = 20 dan 3x - 5y = 4 maka nilai 6x - 4y =

5x - 3y = 20 |x3
3x - 5y = -4 |x 5

15x - 9y = 60
15x - 25y = -20
___________ -
16y = 80
y = 5

5x - 3 y = 20
5x - 3 . 5 = 20
5x - 15 = 20
5x = 35
x = 7

Nilai 6 x - 4 y
= 6 . 7 - 4 . 5
= 42 - 20
= 22