估算.183÷9 21×38 49×71 123÷6.
(x- 4.5)=7x-25%x=10
3x=5(32-x)0.36×5-x=
2(x-2)+2=x+13-x=2-5(x-1)
8-x=3-x=
2x+3x=3.153.4x=8.6-1.8