$\frac{9x}{y}\ast <!--\; \ast \; -->\frac{y}{24x}=\frac{3}{1}\ast <!--\; \ast \; -->\frac{1}{8}=\frac{3}{8}$

$\frac{m^2{n}^3}{25t}\ast <!--\; \ast \; -->(\frac{-<!--\; -\; -->5t}{m{n}^2})=\frac{mn}{5}\ast <!--\; \ast \; -->(\frac{-<!--\; -\; -->1}{1})=-<!--\; -\; -->\frac{mn}{5}$

$\frac{16a^4}{21b^5}\ast <!--\; \ast \; -->\frac{9b^2}{10a^3}=\frac{8a}{7b^3}\ast <!--\; \ast \; -->\frac{3}{5}=\frac{24a}{35b^3}$

$26m^2\ast <!--\; \ast \; -->\frac{3n^2}{13m^4}=2\ast <!--\; \ast \; -->\frac{3n^2}{m^2}=\frac{6n^2}{m^2}$

$\frac{24t^7}{16u^3}\ast <!--\; \ast \; -->34u^5=\frac{3t^7}{1}\ast <!--\; \ast \; -->17u^2=51t^7{u}^2$

$\frac{4x^5{y}^2}{7a^{3}b}\ast <!--\; \ast \; -->\frac{21x{b}^2}{10y^3{a}^2}\ast <!--\; \ast \; -->\frac{25a^{5}y}{3x^{4}b}=\frac{21\ast <!--\; \ast \; -->100x^6{y}^3{a}^5{b}^2}{21\ast <!--\; \ast \; -->10x^4{y}^3{a}^5{b}^2}=10x^2$