①15÷x=
②x-×=21
③
④
×=
× =
3÷=
÷ 3=
=
0.48×=
×÷×=
46×9=460-=
67×9=-=
5.2÷0.04= 1.32+0.8= 8 ÷8= 25+7.5=
51.51÷51= + ÷ = 1.5×2÷1.5×2= 149÷30≈