$\frac{3a^2}{c}\ast <!--\; \ast \; -->\frac{a^2}{c}=\frac{3a^2\ast <!--\; \ast \; -->a^2}{c\ast <!--\; \ast \; -->c}=\frac{3a^4}{c^2}$

$\frac{2a}{b}\ast <!--\; \ast \; -->\frac{b}{8a}=\frac{1}{1}\ast <!--\; \ast \; -->\frac{1}{4}=\frac{1}{4}$

$\frac{x}{yz}\ast <!--\; \ast \; -->\frac{y^4}{5x}=\frac{1}{z}\ast <!--\; \ast \; -->\frac{y^3}{5}=\frac{y^3}{5z}$

$\frac{3m}{16n^2}\ast <!--\; \ast \; -->8n^6=\frac{3m}{2}\ast <!--\; \ast \; -->n^4=\frac{3m{n}^4}{2}$

$14m^9\ast <!--\; \ast \; -->\frac{n^2}{7m^3}=2m^6\ast <!--\; \ast \; -->\frac{n^2}{1}=2m^6{n}^2$

$\frac{15a^4}{b^{12}}\ast <!--\; \ast \; -->\frac{b^6}{10a^2}=\frac{3a^2}{b^6}\ast <!--\; \ast \; -->\frac{1}{2}=\frac{3a^2}{2b^6}$

$\frac{48ab}{17c^4}\ast <!--\; \ast \; -->\frac{51b{c}^5}{40a^4}=\frac{6b}{1}\ast <!--\; \ast \; -->\frac{3bc}{5a^3}=\frac{18b^{2}c}{5a^3}$

$\frac{21c^3}{13p^2}\ast <!--\; \ast \; -->\frac{39p}{28c^2}=\frac{3c}{p}\ast <!--\; \ast \; -->\frac{3}{4}=\frac{9c}{4p}$