×40=
÷=
×=
×2.1=
0÷=
20×45%=
25%÷=
1÷×=
×÷×=
进价
降价前售价
降价后售价
56元/个
78元/个
48元/个
+0.375= 2.5×(17×4)= 631÷89≈
0.32= ×÷×=