Bài 3
\(a,=\dfrac{5}{7}\left(\dfrac{5}{11}+\dfrac{2}{11}-\dfrac{14}{11}\right)\\ =\dfrac{5}{7}.\left(-\dfrac{7}{11}\right)\\ =-\dfrac{5}{11}\\ b,=-\dfrac{7}{9}.\left(\dfrac{4}{11}+\dfrac{7}{11}\right)+\dfrac{7}{9}\\ =-\dfrac{7}{9}+\dfrac{7}{9}\\ =0\\ c,=-\dfrac{3}{8}\left(\dfrac{1}{6}+\dfrac{5}{6}\right)-\dfrac{10}{16}\\ =-\dfrac{3}{8}-\dfrac{10}{16}\\ =\dfrac{-3.2-10}{16}\\ =-1\\ d,=\dfrac{5}{7}\left(\dfrac{2+12-1}{11}\right)\\ =\dfrac{5}{7}.\dfrac{13}{11}\\ =\dfrac{65}{77}\)
\(a,=\dfrac{5}{7}\cdot\left(\dfrac{5}{11}+\dfrac{2}{11}-\dfrac{14}{11}\right)=\dfrac{5}{7}\cdot-\dfrac{7}{11}=-\dfrac{5}{11}\)
\(b,=-\dfrac{7}{9}\cdot\dfrac{4}{11}+-\dfrac{7}{9}\cdot\dfrac{7}{11}+\dfrac{-7}{9}\cdot\left(-1\right)=-\dfrac{7}{9}\cdot\left(\dfrac{4}{11}+\dfrac{7}{11}-1\right)\\ =-\dfrac{7}{9}\cdot0=0\)
\(c,=-\dfrac{3}{8}\cdot\left(\dfrac{1}{6}+\dfrac{5}{6}\right)+\dfrac{-5}{8}=-\dfrac{3}{8}\cdot1+\dfrac{-5}{\cdot}=-\dfrac{3}{8}+-\dfrac{5}{8}=-1\)
\(d,=\dfrac{5}{7}\cdot\left(\dfrac{2}{11}+\dfrac{12}{11}-1\right)=\dfrac{5}{7}\cdot\dfrac{3}{11}=\dfrac{15}{77}\)
giúp em câu 4,5,7 vs ạ em cảm ơn ;-;
