[tex]\frac{p^2n^4(p^{10}n^5)^{\frac{2}{5}}}{(p^{-8}n^3)p^{12}n^5} = \frac{p^2n^4p^{10\times \frac{2}{5}}n^{5\times \frac{2}{5}}}{(p^{-8+12}n^{3+5})} = \frac{p^2n^4 p^4n^2}{p^4n^8}= \frac{p^6n^6}{p^4n^8}= \frac{p^2}{n^2}[/tex]
