《2025年名校课堂七年级数学上册北师大版山西专版》

计算：
(1)$(-10)×(-7.32)×(-0.1)$。
(2)$(-20)×(-1\frac {1}{5})×(-0.3)×5$。
(3)$25×\frac {3}{4}-(-25)×\frac {1}{2}+25×(-\frac {1}{4})$。
(4)$(\frac {2}{3}-\frac {3}{4}+\frac {1}{6})÷(-\frac {1}{24})$。
(5)$(-36)×99\frac {71}{72}$。
(6)$[1\frac {2}{13}-(\frac {5}{8}-\frac {1}{6}+\frac {7}{12})×24]÷(-5)$。
(7)$(-\frac {1}{30})÷(\frac {2}{3}-\frac {1}{10}+\frac {1}{6}-\frac {2}{5})$。
(8)$0.7×1\frac {4}{9}+2\frac {3}{4}×(-17)+0.7×\frac {5}{9}+\frac {1}{4}×(-17)$。

答案：
(1)原式= - (10×0.1)×7.32 = - 7.32。
(2)原式$= - (20×0.3)×(\frac{6}{5})= - 6×6 = - 36。$
(3)原式$=25×\frac{3}{4} + 25×\frac{1}{2} - 25×\frac{1}{4}=25×(\frac{3}{4} + \frac{1}{2} - \frac{1}{4})=25×1 = 25。$
(4)原式$=(\frac{2}{3} - \frac{3}{4} + \frac{1}{6})×( - 24)=\frac{2}{3}×( - 24) - \frac{3}{4}×( - 24) + \frac{1}{6}×( - 24)= - 16 + 18 - 4 = - 2。$
(5)原式$=( - 36)×(100 - \frac{1}{72})= - 3600 + \frac{1}{2} = - 3599\frac{1}{2}。$
(6)原式$=[1\frac{2}{13} - (15 - 4 + 14)]÷( - 5)=(\frac{15}{13} - 25)×( - \frac{1}{5})=\frac{15}{13}×( - \frac{1}{5}) - 25×( - \frac{1}{5})=\frac{3}{13} + 5 = 4\frac{10}{13}。$
(7)原式的倒数为$(\frac{2}{3} - \frac{1}{10} + \frac{1}{6} - \frac{2}{5})÷( - \frac{1}{30})=(\frac{2}{3} - \frac{1}{10} + \frac{1}{6} - \frac{2}{5})×( - 30)=\frac{2}{3}×( - 30) - \frac{1}{10}×( - 30) + \frac{1}{6}×( - 30) - \frac{2}{5}×( - 30)= - 20 - ( - 3) + ( - 5) - ( - 12)= - 10。$故原式$= - \frac{1}{10}。$
(8)原式$=(0.7×1\frac{4}{9} + 0.7×\frac{5}{9}) + [2\frac{3}{4}×( - 17) + \frac{1}{4}×( - 17)]=0.7×(1\frac{4}{9} + \frac{5}{9}) + ( - 17)×(2\frac{3}{4} + \frac{1}{4})=0.7×2 + ( - 17)×3 = 1.4 - 51 = - 49.6。$