Ответ:а) \(\frac{b}{a^2}=\frac{a^2b}{a^4}\).б) \(\frac{x}{2y}=\frac{2xy^2}{4y^3}\).а) \(\frac5{3a^2b}=\frac{5\cdot7ab}{3a^2b\cdot7ab}=\frac{35ab}{21a^3b^2}\).б) \(\frac{3c}{7y^5}=\frac{3c\cdot2xy}{7y^5\cdot2xy}=\frac{6cxy}{14xy^6}\).