①
②
③
④
①x:3=:
②=
③:=:x
④:x=3:12
⑤:x=5%:0.6
⑥=
+= ﹣= 3.5×= 2÷0.5=
①700﹣1.5÷7×30
②14.1﹣4.63+1.6﹣2.37
③(+)×9+
④÷[×(﹣)]