13) \(\dfrac{9^8\cdot8^6}{16^4\cdot3^{17}}\)
\(=\dfrac{\left(3^2\right)^8\cdot\left(2^3\right)^6}{\left(2^4\right)^4\cdot3^{17}}\)
\(=\dfrac{3^{16}\cdot2^{18}}{2^{16}\cdot3^{17}}\)
\(=\dfrac{1\cdot2^2}{1\cdot3}\)
\(=\dfrac{4}{3}\)
14) \(\dfrac{2^{11}\cdot9^2}{3^5\cdot16^2}\)
\(=\dfrac{2^{11}\cdot\left(3^2\right)^2}{3^5\cdot\left(2^4\right)^2}\)
\(=\dfrac{2^{11}\cdot3^4}{3^5\cdot2^8}\)
\(=\dfrac{2^3\cdot1}{3\cdot1}\)
\(=\dfrac{8}{3}\)
15) \(\dfrac{4^{10}\cdot25^7}{5^{14}\cdot8^6}\)
\(=\dfrac{\left(2^2\right)^{10}\cdot\left(5^2\right)^7}{5^{14}\cdot\left(2^3\right)^6}\)
\(=\dfrac{2^{20}\cdot5^{14}}{5^{14}\cdot2^{18}}\)
\(=\dfrac{2^2\cdot1}{1\cdot1}\)
\(=4\)