a: \(x:5=\dfrac{15}{14}\\ \Rightarrow x=\dfrac{15}{70}=\dfrac{3}{14}\)
a) \(x:5=\dfrac{4}{7}+\dfrac{1}{2}\)
\(\dfrac{x}{5}=\dfrac{15}{14}\)
\(\Rightarrow x=\dfrac{5.15}{14}=\dfrac{75}{14}\)
b) \(\dfrac{1}{3}+\dfrac{2}{9}\times\dfrac{3}{4}=\dfrac{1}{3}+\dfrac{1}{6}=\dfrac{2}{6}+\dfrac{1}{6}=\dfrac{3}{6}=\dfrac{1}{2}\)
\(x\div5=\dfrac{4}{7}+\dfrac{1}{2}\)
\(x\div5=\dfrac{15}{14}\)
\(x=\dfrac{15}{14}\times5\)
\(x=\dfrac{75}{14}\)
b)
\(\dfrac{1}{3}+\dfrac{2}{9}\times\dfrac{3}{4}\)
\(=\dfrac{1}{3}+\dfrac{1}{6}\)
\(=\dfrac{1}{2}\)