Икс минус 1/6=7/9игрик плюс 2/5=1/2
x-1/6=7/9y+2/5=1/2
x-1/6=1/2
7/9y+2/5=1/2
x=2/3
y=9/70
(x,y)=(2/3,9/70)
2/3-1/6=7/9×9/70+2/5=1/2
1/2=1/2=1/2