3x﹣1.5x=22.5
x:0.8=0.25:
1+x=
= 1.8:5.4=x:2.4 x:8=:
x﹣20%x=40 5x+18=48 :=15:x
① × + ÷
② × + ÷5
③18-5 -
④99×
⑤14:0.5=4:x
⑥15x-2.4x=37.8