\(a.y:\dfrac{2}{3}=\dfrac{4}{9}\times3\\y:\dfrac{2}{3}=\dfrac{4}{3}\\ y=\dfrac{4}{3}\times\dfrac{2}{3}\\ y=\dfrac{8}{9}\\ b.\dfrac{5}{6}+\dfrac{y}{12}=\dfrac{7}{6}\\ \dfrac{y}{12}=\dfrac{7}{6}-\dfrac{5}{6}\\ \dfrac{y}{12}=\dfrac{2}{6}\\ y\times6=12\times2=24\\ y=24:6\\ y=4 \)
\(a,y:\dfrac{2}{3}=\dfrac{4}{9}.3\)
\(y:\dfrac{2}{3}=\dfrac{4}{3}\)
\(y=\dfrac{4}{3}.\dfrac{2}{3}\)
\(y=\dfrac{8}{9}\)
\(b,\dfrac{5}{6}+\dfrac{y}{12}=\dfrac{7}{6}\)
\(\dfrac{y}{12}=\dfrac{7}{6}-\dfrac{5}{6}\)
\(\dfrac{y}{12}=\dfrac{2}{6}\)
\(y.6=12.2\)
\(y.6=24\)
\(y=24:6\)
\(y=4\)