a)\(6:\left(\frac{\frac{3}{5}x+3}{20}+9\right)=\frac{3}{5}\)

\(\frac{\frac{3}{5}x+3}{20}+9=6:\frac{3}{5}\)

\(\frac{\frac{3}{5}x+3}{20}+9=6.\frac{5}{3}\)

\(\frac{\frac{3}{5}x+3}{20}+9=10\)

\(\frac{\frac{3}{5}x+3}{20}=10-9\)

\(\left(\frac{3}{5}x+3\right):20=1\)

\(\frac{3}{5}x+3=1.20\)

\(\frac{3}{5}x+3=20\)

\(\frac{3}{5}x=20-3\)

\(\frac{3}{5}x=17\)

\(x=17:\frac{3}{5}\)

\(x=17.\frac{5}{3}\)

\(x=\frac{85}{3}\)

b)l x+3 l = l -9 l

 l x+3l=9

\(\orbr{\begin{cases}x+3=9\\x+3=-9\end{cases}\Rightarrow\orbr{\begin{cases}x=9-3\\x=-9-3\end{cases}\Rightarrow}\orbr{\begin{cases}x=6\\x=-12\end{cases}}}\)

1) \(x=\frac{99}{196}\)

2) \(x=-2\)

3) \(x\approx-0,59\)

giup mk giải rõ dc ko

Bạn đăng ít một thôi!

mk lỡ đăng rồi bạn ạ 

\(a)\frac{8}{9}x-\frac{2}{3}=\frac{1}{3}x+1\frac{1}{3}\)

\(\Rightarrow\frac{8}{9}x-\frac{1}{3}x=\frac{2}{3}+1\frac{1}{3}\)

\(\Rightarrow\frac{5}{9}x=\frac{2}{3}+\frac{4}{3}\)

\(\Rightarrow\frac{5}{9}x=2\Rightarrow x=2\div\frac{5}{9}=\frac{18}{5}\)

\(b)(\frac{-2}{5}+\frac{3}{7})-(\frac{4}{9}+\frac{12}{20}-\frac{13}{25})+\frac{7}{35}\)

\(=\frac{1}{35}-(\frac{4}{9}+\frac{3}{5}-\frac{13}{25})+\frac{1}{5}\)

\(=\frac{1}{35}-(\frac{4}{9}+\frac{15}{25}-\frac{13}{25})+\frac{1}{5}\)

\(=\frac{1}{35}-(\frac{4}{9}+\frac{2}{25})+\frac{1}{5}\)

\(=\frac{1}{35}-\frac{118}{25}+\frac{1}{5}\)

Làm nốt

\(=\frac{16}{5}.\frac{15}{16}-\left(\frac{3}{4}+\frac{2}{7}\right):\left(\frac{-29}{28}\right)\)

\(=3-\left(\frac{21}{28}+\frac{8}{28}\right):\left(\frac{-29}{28}\right)\)

\(=3-\left(\frac{29}{28}\right).\left(\frac{-28}{29}\right)\)

\(=3-\left(-1\right)\)

\(=4\)

b)   \(=\left(\frac{1}{4}+\frac{25}{2}-\frac{5}{16}\right):\left(12-\frac{7}{12}:\left(\frac{3}{8}-\frac{1}{12}\right)\right)\)

       \(=\left(\frac{4}{16}+\frac{200}{16}-\frac{5}{16}\right):\left(12-\frac{7}{12}:\left(\frac{3.3}{2.3.4}-\frac{2}{2.3.4}\right)\right)\)

     \(=\left(\frac{199}{16}\right):\left(12-\frac{7}{12}:\left(\frac{9}{24}-\frac{2}{24}\right)\right)\)

      \(=\frac{199}{16}:\left(12-\frac{7}{12}.\frac{24}{7}\right)\)

    \(=\frac{199}{16}:\left(12-2\right)\)

\(=\frac{199}{16}:10\)

\(=\frac{199}{160}\)

c)   \(\left(\frac{-3}{5}+\frac{5}{11}\right):\frac{-3}{7}+\left(\frac{-2}{5}+\frac{6}{5}\right):\frac{-3}{7}\)

\(\left(\frac{-33}{55}+\frac{25}{55}\right):\frac{-3}{7}+\left(\frac{4}{5}\right):\frac{-3}{7}\)

\(\left(\frac{-8}{55}\right).\frac{-7}{3}+\frac{4}{5}.\frac{-7}{3}\)

\(\frac{-7}{3}\left(\frac{-8}{55}+\frac{4}{5}\right)\)

\(\frac{-7}{3}.\frac{36}{55}=\frac{-84}{55}\)

giờ mk phải đi ngủ r mai mk làm cho