Cipu 24*4=70+x => x=24*4-70=96-70=26
y=280:7+120=40+120=160
x=240-400:10=240-40=200
y=80*7-60=560-60=500
b:6=70-57=> b=13*6=78
y=510:3-20=170-20=150
b=390:3-17=130-17=113