《2025年假日数学吉林出版集团股份有限公司五年级北师大版B版》

5. 脱式计算。
$(\frac {9}{4}-\frac {2}{2})×\frac {8}{3}$ $\frac {9}{26}÷\frac {8}{13}×\frac {8}{27}$ $\frac {2}{5}×(\frac {3}{4}+\frac {1}{5})÷\frac {19}{10}$
$\frac {6}{13}÷[\frac {7}{11}×(1-\frac {3}{7})]$ $\frac {7}{12}-(\frac {1}{4}-\frac {5}{12})$ $\frac {3}{4}-\frac {3}{4}÷3+\frac {3}{5}$

答案： 1. $(\frac{9}{4} - \frac{2}{2})×\frac{8}{3}$
$=(\frac{9}{4} - 1)×\frac{8}{3}$
$=\frac{5}{4}×\frac{8}{3}$
$=\frac{10}{3}$
2. $\frac{9}{26}÷\frac{8}{13}×\frac{8}{27}$
$=\frac{9}{26}×\frac{13}{8}×\frac{8}{27}$
$=\frac{9×13×8}{26×8×27}$
$=\frac{1}{6}$
3. $\frac{2}{5}×(\frac{3}{4}+\frac{1}{5})÷\frac{19}{10}$
$=\frac{2}{5}×(\frac{15}{20}+\frac{4}{20})×\frac{10}{19}$
$=\frac{2}{5}×\frac{19}{20}×\frac{10}{19}$
$=\frac{1}{5}$
4. $\frac{6}{13}÷[\frac{7}{11}×(1 - \frac{3}{7})]$
$=\frac{6}{13}÷[\frac{7}{11}×\frac{4}{7}]$
$=\frac{6}{13}÷\frac{4}{11}$
$=\frac{6}{13}×\frac{11}{4}$
$=\frac{33}{26}$
5. $\frac{7}{12}-(\frac{1}{4}-\frac{5}{12})$
$=\frac{7}{12}-\frac{1}{4}+\frac{5}{12}$
$=(\frac{7}{12}+\frac{5}{12}) - \frac{1}{4}$
$=1 - \frac{1}{4}$
$=\frac{3}{4}$
6. $\frac{3}{4}-\frac{3}{4}÷3+\frac{3}{5}$
$=\frac{3}{4}-\frac{3}{4}×\frac{1}{3}+\frac{3}{5}$
$=\frac{3}{4}-\frac{1}{4}+\frac{3}{5}$
$=\frac{1}{2}+\frac{3}{5}$
$=\frac{5}{10}+\frac{6}{10}$
$=\frac{11}{10}$

6. 解方程。
$\frac {5}{12}x= 55$ $x÷\frac {3}{5}= \frac {5}{12}$ $\frac {2}{5}+x= \frac {5}{7}$

答案： 解：
$\frac{5}{12}x = 55$
$x = 55 ÷ \frac{5}{12}$
$x = 55 × \frac{12}{5}$
$x = 132$
$x ÷ \frac{3}{5} = \frac{5}{12}$
$x = \frac{5}{12} × \frac{3}{5}$
$x = \frac{1}{4}$
$\frac{2}{5} + x = \frac{5}{7}$
$x = \frac{5}{7} - \frac{2}{5}$
$x = \frac{25}{35} - \frac{14}{35}$
$x = \frac{11}{35}$