Question

7．用简便方法计算下面各题．
18.5×$\frac{4}{5}$+18.5×$\frac{1}{5}$
（$\frac{11}{12}$+$\frac{5}{18}$-$\frac{7}{24}$）×72．

Answer 1

分析 ①逆用乘法分配律简算；
②运用乘法分配律简算．

解答 解：①18.5×$\frac{4}{5}$+18.5×$\frac{1}{5}$
=18.5×（$\frac{4}{5}$+$\frac{1}{5}$）
=18.5×1
=18.5

②（$\frac{11}{12}$+$\frac{5}{18}$-$\frac{7}{24}$）×72
=$\frac{11}{12}$×72+$\frac{5}{18}$×72-$\frac{7}{24}$×72
=66+20-21
=86-21
=65．

点评 此题考查了乘法分配律的运用．