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乘法分配
300
$\frac{8}{3}$
$\frac{25}{81}$
$\frac{4}{45}$
$5\frac{5}{6}$
解:
$\begin{aligned}\frac{3}{5}\div\frac{3}{8}\times\frac{1}{12}&=\frac{3}{5}\times\frac{8}{3}\times\frac{1}{12}\\&=\frac{8}{5}\times\frac{1}{12}\\&=\frac{2}{15}\end{aligned}$
解:
$\begin{aligned}55 - 55\times\frac{55}{56}&=55\times(1 - \frac{55}{56})\\&=55\times\frac{1}{56}\\&=\frac{55}{56}\end{aligned}$
解:
$\begin{aligned}(\frac{1}{4}-\frac{1}{20})\times40&=\frac{1}{4}\times40-\frac{1}{20}\times40\\&=10 - 2\\&=8\end{aligned}$
解:
$\begin{aligned}5-\frac{1}{8}\div\frac{2}{13}-\frac{3}{16}&=5-\frac{1}{8}\times\frac{13}{2}-\frac{3}{16}\\&=5-\frac{13}{16}-\frac{3}{16}\\&=5-(\frac{13}{16}+\frac{3}{16})\\&=5 - 1\\&=4\end{aligned}$
解:
$\begin{aligned}\frac{6}{7}\times\frac{1}{4}+\frac{1}{7}\div4&=\frac{6}{7}\times\frac{1}{4}+\frac{1}{7}\times\frac{1}{4}\\&=(\frac{6}{7}+\frac{1}{7})\times\frac{1}{4}\\&=1\times\frac{1}{4}\\&=\frac{1}{4}\end{aligned}$
解:
$\begin{aligned}\frac{3}{4}\times[(\frac{7}{15}-\frac{2}{5})\div\frac{2}{3}]&=\frac{3}{4}\times[(\frac{7}{15}-\frac{6}{15})\div\frac{2}{3}]\\&=\frac{3}{4}\times(\frac{1}{15}\div\frac{2}{3})\\&=\frac{3}{4}\times(\frac{1}{15}\times\frac{3}{2})\\&=\frac{3}{4}\times\frac{1}{10}\\&=\frac{3}{40}\end{aligned}$
C
解:
摘草莓的质量:$\frac{2}{5}\times\frac{5}{8}=\frac{1}{4}$(吨)
草莓比梨少的质量:$\frac{2}{5}-\frac{1}{4}=\frac{8}{20}-\frac{5}{20}=\frac{3}{20}$(吨)
答:六年级同学摘了$\frac{1}{4}$吨草莓,摘的草莓比梨少$\frac{3}{20}$吨。
解:
$(\frac{5}{2}-\frac{2}{5}\times4)\div6$
$=(\frac{5}{2}-\frac{8}{5})\div6$
$=(\frac{25}{10}-\frac{16}{10})\div6$
$=\frac{9}{10}\div6$
$=\frac{9}{10}\times\frac{1}{6}$
$=\frac{3}{20}$(升)
答:每个杯子里倒进饮料$\frac{3}{20}$升。
解:
$\begin{aligned}(\frac{12}{13}+\frac{12}{17}+\frac{12}{19})\div(\frac{4}{13}+\frac{4}{17}+\frac{4}{19})&=3\times(\frac{4}{13}+\frac{4}{17}+\frac{4}{19})\div(\frac{4}{13}+\frac{4}{17}+\frac{4}{19})\\&=3\times1\\&=3\end{aligned}$