Question

Các bn làm nhanh hộ m nhé tuần sau là hạn nộp r nhé :)

Answer 1

\(a=\dfrac{5}{7}.\left(\dfrac{6}{13}+\dfrac{-7}{13}+\dfrac{14}{13}\right)=\dfrac{5}{7}.\dfrac{13}{13}=\dfrac{5}{7}.1=\dfrac{5}{7}\)

\(b=\left(-\dfrac{5}{7}\right).\dfrac{2}{11}+\left(-\dfrac{5}{7}\right).\dfrac{4}{11}+\left(-\dfrac{5}{7}\right).\dfrac{5}{11}=\left(-\dfrac{5}{7}\right).\left(\dfrac{2}{11}+\dfrac{4}{11}+\dfrac{5}{11}\right)\\ =\left(-\dfrac{5}{7}\right).\dfrac{11}{11}=-\dfrac{5}{7}.1=-\dfrac{5}{7}\)

 

 

 

 

Answer 2

a) \(\dfrac{5}{7}\). \(\dfrac{6}{13}+\dfrac{-7}{13}.\dfrac{5}{7}+\dfrac{5}{7}.\dfrac{14}{13}\)

= \(\dfrac{5}{7}.\left(\dfrac{6}{13}+\dfrac{-7}{13}+\dfrac{14}{13}\right)\)

= \(\dfrac{5}{7}.\left[\dfrac{6+\left(-7\right)+14}{13}\right]\)

=\(\dfrac{5}{7}.1\)

=\(\dfrac{5}{7}\)

b)\(\left(\dfrac{-5}{7}\right).\dfrac{2}{11}+\left(\dfrac{-5}{7}\right).\dfrac{14}{11}+\dfrac{5}{7}.\left(\dfrac{-5}{11}\right)\)

=\(\left(\dfrac{-5}{7}\right).\dfrac{2}{11}+\left(\dfrac{-5}{7}\right).\dfrac{14}{11}-\left(\dfrac{-5}{7}\right).\left(\dfrac{-5}{11}\right)\)

=\(\left(\dfrac{-5}{7}\right).\left(\dfrac{2}{11}+\dfrac{14}{11}-\dfrac{-5}{11}\right)\)

= \(\left(\dfrac{-5}{7}\right).\dfrac{21}{11}\)

= \(\dfrac{-15}{11}\)