1)(72-56ab):8=72:8-56ab:8=9-7ab=-7ab+9
2)(64x+4):4=64x:4+4:4=16x+1
3)(9-99y):9=9:9-99y:9=1-11y=-11y+1
1)(72-56ab):8=72:8-56ab:8=9-7ab=-7ab+9
2)(64x+4):4=64x:4+4:4=16x+1
3)(9-99y):9=9:9-99y:9=1-11y=-11y+1