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1. 计算：
(1) $|-5| ÷ (-1\dfrac{2}{7}) ÷ 1.25 × \dfrac{9}{4}$；
(2) $-3 ÷ 1\dfrac{3}{4} × 0.75 × \left|-2\dfrac{1}{3}\right| ÷ 9$；
(3) $(-2\dfrac{1}{3}) × (-1\dfrac{1}{6}) ÷ (-7) × \dfrac{1}{7}$；
(4) $(-80) × (-\dfrac{4}{5}) ÷ |-16| ÷ \dfrac{4}{15}$；
(5) $-1\dfrac{1}{2} ÷ \dfrac{3}{4} ÷ (-0.25) × (-1\dfrac{3}{4})$；
(6) $(-2\dfrac{13}{16}) ÷ (\dfrac{3}{4} × \dfrac{9}{8})$。
(1) $|-5| ÷ (-1\dfrac{2}{7}) ÷ 1.25 × \dfrac{9}{4}$；
(2) $-3 ÷ 1\dfrac{3}{4} × 0.75 × \left|-2\dfrac{1}{3}\right| ÷ 9$；
(3) $(-2\dfrac{1}{3}) × (-1\dfrac{1}{6}) ÷ (-7) × \dfrac{1}{7}$；
(4) $(-80) × (-\dfrac{4}{5}) ÷ |-16| ÷ \dfrac{4}{15}$；
(5) $-1\dfrac{1}{2} ÷ \dfrac{3}{4} ÷ (-0.25) × (-1\dfrac{3}{4})$；
(6) $(-2\dfrac{13}{16}) ÷ (\dfrac{3}{4} × \dfrac{9}{8})$。
答案
(1) $-7$
(2) $-\frac{1}{3}$
(3) $-\frac{1}{18}$
(4) $15$
(5) $-14$
(6) $-\frac{10}{3}$
(2) $-\frac{1}{3}$
(3) $-\frac{1}{18}$
(4) $15$
(5) $-14$
(6) $-\frac{10}{3}$
2. 用简便算法计算：$3\frac{41}{100} × 9\frac{9}{10} × (-\frac{19}{50}) ÷ [\frac{19}{100} × 3\frac{3}{10} × (-1\frac{1}{10})]$
答案
$\frac{93}{5}$
【解析】原式$=\frac{341}{100}×\frac{99}{10}×(-\frac{19}{50})÷[\frac{19}{100}×\frac{33}{10}×(-\frac{11}{10})]=\frac{341}{100}×\frac{99}{10}×(-\frac{19}{50})×\frac{100}{19}×\frac{10}{33}×(-\frac{10}{11})=[\frac{341}{100}×(-\frac{10}{11})]×(\frac{99}{10}×\frac{10}{33})×[(-\frac{19}{50})×\frac{100}{19}]=(-\frac{31}{10})×3×(-2)=\frac{93}{5}$
【解析】原式$=\frac{341}{100}×\frac{99}{10}×(-\frac{19}{50})÷[\frac{19}{100}×\frac{33}{10}×(-\frac{11}{10})]=\frac{341}{100}×\frac{99}{10}×(-\frac{19}{50})×\frac{100}{19}×\frac{10}{33}×(-\frac{10}{11})=[\frac{341}{100}×(-\frac{10}{11})]×(\frac{99}{10}×\frac{10}{33})×[(-\frac{19}{50})×\frac{100}{19}]=(-\frac{31}{10})×3×(-2)=\frac{93}{5}$
