\(a,=\dfrac{4}{5}.\left(\dfrac{3}{7}+\dfrac{4}{7}\right)=\dfrac{4}{5}.\dfrac{7}{7}=\dfrac{4}{5}\\ b,=\dfrac{2}{5}\left(\dfrac{7}{4}-\dfrac{3}{7}\right)\\ =\dfrac{2}{5}.\left(\dfrac{49-12}{28}\right)=\dfrac{2}{5}.\dfrac{37}{28}=\dfrac{37}{70}\)
a) \(\dfrac{4}{5}\times\dfrac{3}{7}+\dfrac{4}{5}\times\dfrac{4}{7}\)
\(=\dfrac{4}{5}\left(\dfrac{3}{7}+\dfrac{4}{7}\right)\)
\(=\dfrac{4}{5}.1\)
\(=\dfrac{4}{5}\)
b) \(\dfrac{2}{5}\times\dfrac{7}{4}-\dfrac{2}{5}\times\dfrac{3}{7}\)
\(=\dfrac{2}{5}\left(\dfrac{7}{4}-\dfrac{3}{7}\right)\)
\(=\dfrac{2}{5}\times\dfrac{37}{28}\)
\(=\dfrac{37}{70}\)
a.\(\dfrac{4}{5}\left(\dfrac{3}{7}+\dfrac{4}{7}\right)=\dfrac{4}{5}\)
b.\(\dfrac{2}{5}\left(\dfrac{7}{4}-\dfrac{3}{7}\right)=\dfrac{2}{5}.\dfrac{37}{28}=\dfrac{37}{70}\)
a)
=4/5x(3/7+4/7)=4/5
b)
=2/5x(7/4-3/7)=37/28 x 2/5=37/70
