24× 69 ×-13× ×40%+0.75 ×
① ②
③ ④
+÷ 25%×28+×72 ÷× (+)×4×3
46÷ 6.8-3.9×+2.8 ÷4+
0.375×5.8+×3.2- (15-14×)×