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NGUYỄN♥️LINH.._.
16 tháng 4 2022 lúc 14:58

hỏi từng câu 1 thôi

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Hoàng Minh Hằng
16 tháng 4 2022 lúc 14:59

tách

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Keiko Hashitou
16 tháng 4 2022 lúc 15:01

hỏi từng câu thôi

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Knight™
16 tháng 4 2022 lúc 15:24

bữa sau đăng ít thôi ._.

1,

\(a,\dfrac{3}{5}+\dfrac{7}{5}=\dfrac{10}{5}=2\)

\(b,\dfrac{1}{6}+\dfrac{-5}{3}=\dfrac{1}{6}+\dfrac{-10}{6}=\dfrac{-9}{6}=\dfrac{-3}{2}\)

\(c,\dfrac{1}{8}-\dfrac{1}{2}=\dfrac{1}{8}-\dfrac{4}{8}=\dfrac{-3}{8}\)

\(d,-5\cdot\dfrac{1}{3}=\dfrac{-5}{3}\)

\(e,\dfrac{-1}{3}\cdot\dfrac{5}{7}=\dfrac{-5}{21}\)

\(f,\dfrac{2}{7}:\dfrac{3}{4}=\dfrac{2}{7}\cdot\dfrac{4}{3}=\dfrac{8}{21}\)

2,

\(a,0,75+\dfrac{-1}{3}-\dfrac{5}{18}=\dfrac{3}{4}+\dfrac{-1}{3}-\dfrac{5}{18}\)

\(=\dfrac{5}{12}-\dfrac{5}{18}=\dfrac{5}{36}\)

\(b,7\dfrac{3}{5}-\left(2\dfrac{5}{7}+5\dfrac{3}{5}\right)\)

\(=\dfrac{38}{5}-\left(\dfrac{19}{7}+\dfrac{28}{5}\right)\)

\(=\dfrac{38}{5}-\dfrac{291}{35}\)

\(=-\dfrac{5}{7}\)

\(c,\dfrac{4}{15}\cdot\dfrac{1}{3}\cdot\dfrac{15}{20}=\dfrac{1}{15}\)

\(d,\dfrac{-1}{9}\cdot\dfrac{15}{22}:\dfrac{-25}{9}\)

\(=\dfrac{-1}{9}\cdot\dfrac{15}{22}\cdot\dfrac{9}{-25}\)

\(=\dfrac{3}{110}\)

3,

\(a,\dfrac{2}{3}+20\%\cdot\dfrac{10}{7}\)

\(=\dfrac{2}{3}+\dfrac{1}{5}\cdot\dfrac{10}{7}\)

\(=\dfrac{2}{3}+\dfrac{2}{7}\)

\(=\dfrac{20}{21}\)

\(b,\dfrac{3}{4}+1\dfrac{4}{5}:\dfrac{3}{2}-1\)

\(=\dfrac{3}{4}+\dfrac{9}{5}\cdot\dfrac{2}{3}-1\)

\(=\dfrac{3}{4}+\dfrac{6}{5}-1\)

\(=\dfrac{19}{20}\)

\(c,\left(2-\dfrac{1}{2}\right)\left(\dfrac{-3}{4}+\dfrac{1}{2}\right)\)

\(=\dfrac{3}{2}\cdot\dfrac{-1}{4}=\dfrac{-3}{8}\)

\(d,-1,5\cdot\left(\dfrac{7}{3}-\dfrac{5}{3}\cdot4\right)\)

\(=-\dfrac{3}{2}\cdot\dfrac{-13}{3}\)

\(=\dfrac{13}{2}\)

4,

\(a,\dfrac{-3}{4}+\dfrac{2}{7}+\dfrac{-1}{4}+\dfrac{3}{5}+\dfrac{5}{7}\)

\(=\left(\dfrac{-3}{4}+\dfrac{-1}{4}\right)+\left(\dfrac{2}{7}+\dfrac{5}{7}\right)+\dfrac{3}{5}\)

\(=-1+1+\dfrac{3}{5}=\dfrac{3}{5}\)

\(b,\dfrac{6}{21}-\dfrac{-12}{44}+\dfrac{10}{14}-\dfrac{1}{-4}-\dfrac{18}{33}\)

\(=\dfrac{43}{44}\)

\(c,-\dfrac{5}{8}\cdot\dfrac{-12}{29}\cdot\dfrac{8}{-10}\cdot5,8\)

\(=-\dfrac{6}{5}\)

\(d,\left(\dfrac{67}{111}+\dfrac{2}{33}-\dfrac{15}{117}\right)\left(\dfrac{1}{3}-25\%-\dfrac{1}{12}\right)\)

\(=\left(\dfrac{67}{111}+\dfrac{2}{33}-\dfrac{15}{117}\right)0\)

\(=0\)

5,

\(a,\dfrac{9}{17}\cdot\dfrac{3}{7}+\dfrac{9}{17}:\dfrac{7}{4}\)

\(=\dfrac{9}{17}\cdot\left(\dfrac{3}{7}+\dfrac{4}{7}\right)\)

\(=\dfrac{9}{17}\)

\(b,\left(\dfrac{-9}{21}\right)\cdot17\dfrac{2}{3}-\left(\dfrac{-3}{5}\right)^2\cdot\dfrac{22}{3}\)

\(=\left(\dfrac{-9}{21}\right)\cdot\dfrac{53}{3}-\dfrac{9}{25}\cdot\dfrac{22}{3}\)

\(=-\dfrac{53}{7}-\dfrac{66}{25}\)

\(=-\dfrac{1787}{175}\)

\(c,\dfrac{6}{7}\cdot\dfrac{8}{13}+\dfrac{6}{13}\cdot\dfrac{9}{7}-\dfrac{4}{13}\cdot\dfrac{6}{7}\)

\(=\dfrac{6}{7}\cdot\left(\dfrac{8}{13}+\dfrac{9}{13}-\dfrac{4}{13}\right)\)

\(=\dfrac{6}{7}\)

câu d bài 5 làm lộn ở bài 4 :")

\(4d,\dfrac{3}{7}\cdot\left(-\dfrac{2}{5}\right)\cdot2\dfrac{1}{3}\cdot20\cdot\dfrac{19}{72}\)

\(=-\dfrac{6}{35}\cdot\dfrac{7}{3}\cdot\dfrac{380}{72}\)

\(=-\dfrac{19}{9}\)

câu 6 ko lm .-.

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