Question

9．計(jì)算下面各題．
$\frac{5}{6}$×$\frac{12}{21}$÷$\frac{7}{15}$；            $\frac{4}{9}$×$\frac{3}{4}$÷$\frac{3}{4}$；           $\frac{3}{4}$÷$\frac{3}{8}$×32；            $\frac{3}{8}$÷$\frac{9}{16}$×9．

Answer 1

分析 這幾道題都是分?jǐn)?shù)乘除法的混合運(yùn)算，只要把除法變成乘法，然后約分求解即可．

解答 解：（1）$\frac{5}{6}$×$\frac{12}{21}$÷$\frac{7}{15}$
=$\frac{5}{6}$×$\frac{12}{21}$×$\frac{15}{7}$
=$\frac{50}{49}$；

（2）$\frac{4}{9}$×$\frac{3}{4}$÷$\frac{3}{4}$
=$\frac{4}{9}$×$\frac{3}{4}$×$\frac{4}{3}$
=$\frac{4}{9}$；

（3）$\frac{3}{4}$÷$\frac{3}{8}$×32
=$\frac{3}{4}$×$\frac{8}{3}$×32
=2×32
=64；

（4）$\frac{3}{8}$÷$\frac{9}{16}$×9
=$\frac{3}{8}$×$\frac{16}{9}$×9
=6

點(diǎn)評(píng) 本題考查了學(xué)生通過(guò)約分對(duì)分?jǐn)?shù)乘除混合運(yùn)題目進(jìn)行簡(jiǎn)算的能力．