Question

17．計(jì)算：0.8×$\frac{2}{11}$+4.8×（-$\frac{2}{7}$）-2.2÷$\frac{3}{7}$+0.8×$\frac{9}{11}$．

Answer 1

分析 把小數(shù)化為分?jǐn)?shù)、把除法化為乘法，然后根據(jù)實(shí)數(shù)運(yùn)算法則進(jìn)行計(jì)算．

解答 解：原式=$\frac{4}{5}$×$\frac{2}{11}$+$\frac{24}{5}$×（-$\frac{2}{7}$）-$\frac{11}{5}$×$\frac{7}{3}$+$\frac{4}{5}$×$\frac{9}{11}$
=$\frac{4}{5}$×（$\frac{2}{11}$+$\frac{9}{11}$）-$\frac{48}{35}$-$\frac{77}{15}$
=$\frac{4}{5}$-$\frac{48}{35}$-$\frac{77}{15}$
=$\frac{84-144-539}{105}$
=-$\frac{599}{105}$．

點(diǎn)評(píng) 本題考查了有理數(shù)的乘法和除法．在進(jìn)行有理數(shù)的乘法運(yùn)算時(shí)，要靈活運(yùn)用運(yùn)算律．