6÷=
×10%=
×8= 15÷1%=
1.05﹣=
÷
= (
﹣
)×
=
×
÷
×
=
+
X=2 X:
=12:
=0.5
÷(1﹣
)×
×
+40%×
÷(
+
) (
+
)×
+
.