10(1-0,2у)-(1-у)=17
10-2у-1+у=17
-у=12
у=-12
проверка:
10(1+0,2*12)-(1+12)=10+24-1-12=17
10-2y-1+y=17
9-y=17
y=9-17
y=-8
10(1-0,2*(-8))-(1-(-8))=10+16-9=17
