0.6∶1.8=x =
5x-x=19.2 30%x+25=40
①23+56x=34
②x:21=49:16
③160×25%-1.3x=17.9
1+12x=1.6 25%x-9%x=48 3.2:x=25:12
75%:0.8=x:25 16x+0.6=12.6 34×(12x-4)=8.4