bantuin dong caranya

[tex]a) \\ \frac{log\ a^{4}+log\ a^{16} }{log\ a^{8} } \\ \frac{log\ a^{4}.a^{16} }{log\ a^{8} } \\ \frac{log\ a^{20} }{ log\ a^{8} } \\ ^{ a^{8} } log\ a^{20} \\ \frac{20}{8}\ ^{a} log\ a \\ \frac{5}{2} \\ \\ b) \\ 5^{-3}= \frac{1}{5^{3}} = \frac{1}{125} [/tex]