2x+1.5x=17.5 x:0.4=5:4
3x+6=12.6 :x=:
3x﹣1.5x=15 :=:x 9:0.2=x:
9.2x+1.3x=31.5 x:=:2 =
7.2:x=
解:3.6x=57.6
3.6x÷3.6=57.6÷3.6
x=16