x : (6*10) =128-68
12-40:c=4
(30-y) :2=92
20(x:9)=4

1)×:(6*10)=128-68×:60=60×=60*60×=36002)12-40:с=440:c=12-440:c=8c=40:8c=53)(30-y):2=9230-y=92*230-y=184y=30-184y=-15420(x:9)=4x:9=20:4x:9=5x=5*9x=40