a: \(=\dfrac{8}{15}\cdot\dfrac{1}{4}=\dfrac{8}{60}=\dfrac{2}{15}\)
b: \(=\dfrac{2}{5}\left(\dfrac{3}{7}+\dfrac{4}{7}\right)=\dfrac{2}{5}\)
\(a,\dfrac{8}{5}\times\dfrac{1}{4}=\dfrac{2}{5}\)
\(b,\dfrac{2}{5}\times\left(\dfrac{3}{7}+\dfrac{4}{7}\right)=\dfrac{2}{5}\)
a,(1/3+1/5).1/4
=8/15.1/4
2/15
b,2/5.2/7+2/5.4/7
=2/5.(2/7+5/7)
=2/5.1
=2/5
a)\(\left(\dfrac{5}{15}+\dfrac{3}{15}\right)\times\dfrac{1}{4}=\dfrac{8}{15}\times\dfrac{1}{4}=\dfrac{8}{60}=\dfrac{2}{15}\)
b) \(\dfrac{2}{5}\times\left(\dfrac{3}{7}+\dfrac{4}{7}\right)=\dfrac{2}{5}\times\dfrac{7}{7}=\dfrac{2}{5}\times1=\dfrac{2}{5}\)
