Tentukan titik potong garis 7x + 3y - 2 = 0 dan 2x - y + 15 = 0

7x + 3y - 2 = 0
7x + 3y = 2

2x - y + 15 = 0
2x - y = - 15

ttk potong
7x + 3y = 2
2x - y = - 15 |×3
maka
7x + 3y = 2
6x - 3y = - 45
-------------------(+)
13x = - 43
x = - 43/13
disubtitusi ke pers
2x - y = - 15
2(-43/13) - y = - 15
- 86/13 - y = - 15 (dikali 13)
- 86 - 13y = - 195
- 13y = - 195 + 86
- 13y = - 109
y = 109/13
ttk potong = { - 43/13 , 109/13}