第15页

信息发布者:
解:
$\begin{aligned}\frac{5}{8}\div\frac{16}{7}\div\frac{14}{11}&=\frac{5}{8}\times\frac{7}{16}\times\frac{11}{14}\\&=\frac{5\times7\times11}{8\times16\times14}\\&=\frac{385}{1792}\\&=\frac{55}{256}\end{aligned}$
解:
$\begin{aligned}\frac{3}{8}\times\frac{5}{6}\times\frac{24}{35}&=\frac{3\times5\times24}{8\times6\times35}\\&=\frac{360}{1680}\\&=\frac{3}{14}\end{aligned}$
解:
$\begin{aligned}\frac{19}{26}\div\frac{38}{55}\times\frac{5}{11}&=\frac{19}{26}\times\frac{55}{38}\times\frac{5}{11}\\&=\frac{19\times55\times5}{26\times38\times11}\\&=\frac{5225}{10868}\\&=\frac{25}{52}\end{aligned}$
解:
$\begin{aligned}\frac{5}{8}x&=\frac{4}{5}\\x&=\frac{4}{5}\div\frac{5}{8}\\x&=\frac{4}{5}\times\frac{8}{5}\\x&=\frac{32}{25}\end{aligned}$
解:
$\begin{aligned}\frac{3}{4}+x&=\frac{7}{4}\\x&=\frac{7}{4}-\frac{3}{4}\\x&=1\end{aligned}$
解:
$\begin{aligned}3.6:\frac{3}{5}&=(3.6\times5):(\frac{3}{5}\times5)\\&=18:3\\&=6:1\\&=6\end{aligned}$
解:
$\begin{aligned}4200dm^3:\frac{9}{100}dm^3&=(4200\times100):(\frac{9}{100}\times100)\\&=420000:9\\&=(420000\div3):(9\div3)\\&=140000:3\\&=\frac{140000}{3}\end{aligned}$

解:
$\begin{aligned}\frac{8}{9}×\frac{8}{9}\div4&=\frac{64}{81}\div4\\&=\frac{64}{81}×\frac{1}{4}\\&=\frac{16}{81}(平方分米)\end{aligned}$
答:这个长方形的面积是​$\frac {16}{81}$​平方分米。
解:
$\begin{aligned}40\div\frac{4}{7}\times\frac{7}{10}&=40\times\frac{7}{4}\times\frac{7}{10}\\&=70\times\frac{7}{10}\\&=49(人)\end{aligned}$
答:参加声乐组的有49人。