penyelesaian dari sistem persamaan x - y = 12 dan x + 4y = 17 adalah...

x - y = 12
x + 4y = 17
---------------(-)
- 5y = - 5
y = 1

subtitusi
x - y = 12
x - 1 = 12
x = 12 + 1
x = 13

hp = ( 13 , 1 )

x _y = 12
x + 4 y= 17
_______ _
- 5y = _ 5
y = 1

x _ y = 12
x _ 1 = 12
x = 12 + 1
x = 13