Question

5．計(jì)算：[$\frac{5}{8}×（\frac{3}{4}-0.15）+7.8$]÷$8\frac{4}{5}$．

Answer 1

分析 根據(jù)分?jǐn)?shù)四則混合運(yùn)算的運(yùn)算順序可知，先計(jì)算小括號里面的減法，再計(jì)算中括號外面的乘法和加法，最后計(jì)算中括號外面的除法即可得到答案．

解答 解：[$\frac{5}{8}×（\frac{3}{4}-0.15）+7.8$]÷$8\frac{4}{5}$
=[$\frac{5}{8}$×（$\frac{3}{4}$-$\frac{3}{20}$）+7.8]÷$8\frac{4}{5}$
=[$\frac{5}{8}$×$\frac{3}{5}$+7.8]÷$8\frac{4}{5}$
=[$\frac{3}{8}$+7.8]÷$8\frac{4}{5}$
=[$\frac{3}{8}$+$\frac{39}{5}$]÷8$\frac{4}{5}$
=[$\frac{15}{40}$+$\frac{312}{40}$]÷8$\frac{4}{5}$
=$\frac{327}{40}$÷$\frac{44}{5}$
=$\frac{327}{352}$．

點(diǎn)評 此題主要考查的是分?jǐn)?shù)、小數(shù)四則混合運(yùn)算的計(jì)算方法應(yīng)用．