×4=
4÷ =
12:4=
× =
1﹣ =
1.6:0.8=
﹣ =
1:5=
①x﹣40%x=12
②15x﹣30=15
③0.5x+ x=6.
①( ﹣ )×24
②15÷15×
③2÷( + )
①16:20
②0.7:0.8
③ : .