①x:0.8=5:16
②15:x=8:
③3.5∶7=10∶x
④ =
⑤ : = :x
⑥(3.5-x):7=0.4:1.4
①×8××1.25
②5.02-1.37-2.63
③37×
④+7÷(-)
⑤44×(-)
⑥6×+13÷4-19×25%
①700﹣1.5÷7×30
②14.1﹣4.63+1.6﹣2.37
③(+)×9+
④÷[×(﹣)]