第48页

信息发布者：
解:
$\begin{aligned}&5\frac{3}{5}+(-1\frac{7}{8})+2\frac{2}{5}+(-3\frac{5}{12})+2\frac{7}{8}+(-12\frac{7}{12})\\=&(5\frac{3}{5}+2\frac{2}{5})+[(-1\frac{7}{8})+2\frac{7}{8}]+[(-3\frac{5}{12})+(-12\frac{7}{12})]\\=&8 + 1+(-16)\\=&9 - 16\\=& - 7\end{aligned}$
解:
$\begin{aligned}&(-12.5)×(+317)×(-\frac{4}{5})×(-0.1)\\=&(-12.5)×(-0.1)×(+317)×(-\frac{4}{5})\\=&1.25×317×(-0.8)\\=&1.25×(-0.8)×317\\=& - 1×317\\=& - 317\end{aligned}$
解:
​$\begin {aligned}&-1^2-(\frac {2}{3}-\frac {7}{8}+\frac {1}{12}-\frac {5}{6})×(-24)\\=&-1-[\frac {2}{3}×(-24)-\frac {7}{8}×(-24)+\frac {1}{12}×(-24)-\frac {5}{6}×(-24)]\\=&-1-(-16 + 21-2 + 20)\\=&-1-(5 - 2+20)\\=&-1-(3 + 20)\\=&-1 - 23\\=& - 24\end {aligned}$​
解:
$\begin{aligned}&48\frac{24}{25}\div(-48)\\=&(48+\frac{24}{25})\div(-48)\\=&48\div(-48)+\frac{24}{25}\div(-48)\\=&-1-\frac{24}{25}×\frac{1}{48}\\=&-1-\frac{1}{50}\\=&-1\frac{1}{50}\end{aligned}$
解:
$\begin{aligned}&7777×138\frac{7}{9}+\frac{2}{9}\div(-\frac{1}{7777})-38\frac{5}{9}×7777\\=&7777×138\frac{7}{9}+\frac{2}{9}×(-7777)-38\frac{5}{9}×7777\\=&7777×(138\frac{7}{9}-\frac{2}{9}-38\frac{5}{9})\\=&7777×(138\frac{5}{9}-38\frac{5}{9})\\=&7777×100\\=&777700\end{aligned}$
解:
$\begin{aligned}&(-\frac{4}{5})×\frac{5}{13}-(-\frac{3}{5})\div(-2\frac{3}{5})-\frac{5}{13}×(-1\frac{3}{5})\\=&(-\frac{4}{5})×\frac{5}{13}-(-\frac{3}{5})\div(-\frac{13}{5})-\frac{5}{13}×(-\frac{8}{5})\\=&(-\frac{4}{5})×\frac{5}{13}-\frac{3}{5}×\frac{5}{13}+\frac{5}{13}×\frac{8}{5}\\=&\frac{5}{13}×(-\frac{4}{5}-\frac{3}{5}+\frac{8}{5})\\=&\frac{5}{13}×\frac{1}{5}\\=&\frac{1}{13}\end{aligned}$
解:
$\begin{aligned}&(-\frac{1}{36})\div(\frac{1}{3}-\frac{5}{6}+\frac{5}{12}-\frac{2}{9}-2\frac{1}{4})\\=&(-\frac{1}{36})\div(\frac{12}{36}-\frac{30}{36}+\frac{15}{36}-\frac{8}{36}-\frac{81}{36})\\=&(-\frac{1}{36})\div\frac{12 - 30+15 - 8 - 81}{36}\\=&(-\frac{1}{36})\div\frac{-92}{36}\\=&(-\frac{1}{36})×(-\frac{36}{92})\\=&\frac{1}{92}\end{aligned}$
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