1/2x–1/4y=1/4 ; 1/3x–1/2y=-5/6, Nilai x–y adalah...

eliminasi y
1/2x-1/4y=1/4 |×4| 2x -y=1
1/3x-1/2y=-5/6 |×2| 2/3x-y=-10/6
___________ -
4/3x =16/6
x = (16/6)×(3/4)
x = 2
subtitusi x ke persamaan
1/2x-1/4y=1/4
1 -1/4y=1/4
y=(1/4-1)/-1/4
y=3

x-y = 2-3 = -1