Question

\(\dfrac{-5}{13}\)✖\(\dfrac{3}{7}\)-\(\dfrac{2}{17}\)✖\(\dfrac{8}{13}\)+\(\dfrac{5}{13}\)✖\(\dfrac{1}{7}\)

Giải hộ mình nhé có cả lời giải đấy

ok.mình cho 1 tim

 

Answer 1

Ta có: \(\dfrac{-5}{13}\cdot\dfrac{3}{7}-\dfrac{2}{17}\cdot\dfrac{8}{13}+\dfrac{5}{13}\cdot\dfrac{1}{7}\)

\(=\dfrac{5}{13}\left(-\dfrac{3}{7}+\dfrac{1}{7}\right)-\dfrac{2}{17}\cdot\dfrac{8}{13}\)

\(=\dfrac{5}{13}\cdot\dfrac{-2}{7}-\dfrac{2}{17}\cdot\dfrac{8}{13}\)

\(=\dfrac{-10}{91}-\dfrac{16}{221}\)

\(=\dfrac{-282}{1547}\)

 

Answer 2

\(\dfrac{-5}{13}.\dfrac{3}{7}-\dfrac{2}{17}.\dfrac{8}{13}+\dfrac{5}{13}.\dfrac{1}{7}\) 

\(=\dfrac{5}{13}.\dfrac{-3}{7}-\dfrac{2}{17}.\dfrac{8}{13}+\dfrac{5}{13}.\dfrac{1}{7}\)

\(=\dfrac{5}{13}.\left(\dfrac{-3}{7}+\dfrac{1}{7}\right)+\dfrac{-2}{17}.\dfrac{8}{13}\) 

\(=\dfrac{5}{13}.\dfrac{-2}{7}+\dfrac{-2}{13}.\dfrac{8}{17}\)

\(=\dfrac{-2}{13}.\dfrac{5}{7}+\dfrac{-2}{13}.\dfrac{8}{17}\) 

\(=\dfrac{-2}{13}.\left(\dfrac{5}{7}+\dfrac{8}{17}\right)\) 

\(=\dfrac{-2}{13}.\dfrac{141}{119}\) 

\(=\dfrac{-282}{1547}\)