8. x+1075=3806
x=3806-1075
x=2731
___________
2731+1075=3806
3000× x=9000
x=9000÷3000
x=3
____________
3000×3=9000
x-287=593
x=593+287
x=880
__________
880-287=593
x÷5=80
x=80×5
x=400
_________
400÷5=80
x+1540=12320
x=12320-1540
x=10780
____________
10780+1540=12320
8000÷x=400
x=8000÷400
x=20
____________
8000÷20=400