38﹣19=
2.5×4=
=
9﹣0.9=
125×60%=
7.2÷0.4=
4.5a﹣a=
1÷10+=
()×12=
×3÷=
×0=
①
②
③
④
①5x﹣
③5x﹣14×0.5=56
④24:=32:x