\(x:\dfrac{3}{4}=1-\dfrac{2}{5}\\ \Rightarrow x\cdot\dfrac{4}{3}=\dfrac{3}{5}\\ \Rightarrow x=\dfrac{3}{5}:\dfrac{4}{3}=\dfrac{9}{20}\)
\(x:\dfrac{3}{4}=1-\dfrac{2}{5}\)
\(\Rightarrow x:\dfrac{3}{4}=\dfrac{3}{5}\)
\(\Rightarrow x=\dfrac{3}{5}\times\dfrac{3}{4}\)
\(\Rightarrow x=\dfrac{9}{20}\)
x:3/4=1-2/5
x:3/4=3/5
x=3/5x3/4
x=9/20
chúc bạn học tốt <:>