x+320=80×7 x-180=240:3 400-x=275+25

1) х+320=80*7
x=320:80*7
x=210

1)x+320=80×7
x=80×7
x=560-320
x=240
240+320=80×7

2)x-180=240:3
x=240:3
x=80+180
x=240
240-180=240:3

3)400-x=275+25
x=275+25
x=400-300
x=100
400-100=275+25