Question

-5/7 x 4/13 + -5/7 x 9/13 + -2/7
Hộ em vs ạ ^^

Answer 1

\(=\left(-\dfrac{5}{7}\right)\left(\dfrac{4}{13}+\dfrac{9}{13}\right)+\left(-\dfrac{2}{7}\right)=\left(-\dfrac{5}{7}\right).\left(\dfrac{13}{13}\right)+\left(-\dfrac{2}{7}\right)=\left(-\dfrac{5}{7}\right)+\left(-\dfrac{2}{7}\right)=-1\)

Answer 2

\(-\dfrac{5}{7}\cdot\dfrac{4}{13}+\left(-\dfrac{5}{7}\right)\cdot\dfrac{9}{13}+\left(-\dfrac{2}{7}\right)\\ =-\dfrac{5}{7}\left(\dfrac{4}{13}+\dfrac{9}{13}\right)+\left(-\dfrac{2}{7}\right)\\ =-\dfrac{5}{7}\cdot1+\left(-\dfrac{2}{7}\right)\\ =-\dfrac{5}{7}+\left(-\dfrac{2}{7}\right)\\ =-\dfrac{7}{7}=-1\)