giúp mình với câu này kiểu đéo gì 

\(=\dfrac{7}{5}\cdot\dfrac{15}{49}-\left(\dfrac{4}{5}-\dfrac{2}{3}\right):\dfrac{11}{5}\)

\(=\dfrac{3}{7}-\dfrac{2}{15}\cdot\dfrac{5}{11}\)

\(=\dfrac{3}{7}-\dfrac{2}{33}=\dfrac{99-14}{33\cdot7}=\dfrac{85}{231}\)

-5/21 nhé bn

\(1,4x\frac{15}{49}-\left(\frac{4}{5}+\frac{2}{3}\right):2\frac{1}{5}\)

\(=\frac{3}{7}-\frac{22}{15}:2\frac{1}{5}\)

\(=\frac{3}{7}-\frac{2}{3}=-\frac{5}{21}\)

học tốt ~~~

\(1,4\times\frac{15}{49}-\left(\frac{4}{5}+\frac{2}{3}\right)\div2\frac{1}{5}\)

\(=\frac{14}{10}\times\frac{15}{49}-\frac{22}{15}\div\frac{11}{5}\)

\(=\frac{7}{5}\times\frac{15}{49}-\frac{22\times5}{15\times11}\)

\(=\frac{7\times15}{5\times49}-\frac{22\times5}{15\times11}\)

\(=\frac{7\times7\times3\times5}{5\times7\times7}-\frac{11\times2\times5}{3\times5\times11}\)

\(=3-\frac{2}{3}\)

\(=\frac{7}{3}\)

CÂU 1:\(\frac{2}{35}:\left(\frac{3}{5}+\frac{3}{7}\right)\)

           \(=\frac{2}{35}:\frac{36}{35}\)

           \(=\frac{1}{18}\)

CÂU 2:\(\frac{1}{2}\cdot\frac{25}{6}-\left(\frac{4}{3}+\frac{5}{3}\right)\)

    \(=\frac{25}{12}-3\)

     \(=-\frac{11}{12}\)

CÂU 3:\(5\frac{5}{7}-\left(\frac{3}{7}+2\frac{3}{5}\right):\frac{4}{5}\)

   \(=\frac{40}{7}-\left(\frac{3}{7}+\frac{13}{5}\right):\frac{4}{5}\)

   \(=\frac{40}{7}-\frac{106}{35}:\frac{4}{5}\)

   \(=\frac{40}{7}-\frac{53}{14}\)

   \(=\frac{27}{14}\)