a: \(y+\dfrac{1}{2}\cdot\dfrac{1}{3}=\dfrac{3}{4}\)
=>\(y+\dfrac{1}{6}=\dfrac{3}{4}\)
=>\(y=\dfrac{3}{4}-\dfrac{1}{6}=\dfrac{9}{12}-\dfrac{2}{12}=\dfrac{7}{12}\)
b: \(y+\dfrac{1}{2}\cdot\dfrac{1}{5}=\dfrac{3}{10}\)
=>\(y+\dfrac{1}{10}=\dfrac{3}{10}\)
=>\(y=\dfrac{3}{10}-\dfrac{1}{10}=\dfrac{2}{10}=\dfrac{1}{5}\)