∵x/0.5-1/0.7=1; y/5-(y-1)/2=1-(y+2)/5
∴2x-10/7=1,y/10=-6/10
∴x=17/14,y=-6
x/0.5-1/0.7=1
0.7x-0.5=0.35
0.7x=0.85 x=17/14
x/0.5-1/0.7=1;
0.7x-0.5=0.35
0.7x=0.85
x=85/70
x=17/14
y/5-(y-1)/2=1-(y+2)/5
2y-5(y-1)=10-2(y+2)
2y-5y+5=10-2y-4
-3y+2y=6-5
-y=1
y=-1