Question

Please this is due tonight!!! Express given logarithm in terms of a, b and c.

Answer 1

$\textit{Logarithm Change of Base Rule} \\\\ \log_a b\implies \cfrac{\log_c b}{\log_c a}\qquad \qquad c= \begin{array}{llll} \textit{common base for }\\ \textit{numerator and}\\ denominator \end{array} \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ \log_5(18)\implies \cfrac{\log(18)}{\log(5)}\implies \cfrac{\log(2\cdot 3\cdot 3)}{\log(5)}\implies \cfrac{\log(2)+\log(3)+\log(3)}{\log(5)}$

$\begin{cases} \log(3)=a\\ \log(2)=b\\ \log(5)=c \end{cases}\implies \cfrac{b+a+a}{c}\implies \cfrac{b+2a}{c} \\\\[-0.35em] ~\dotfill\\\\ \log_5^2(18)\implies [\log_5(18)]^2\implies \left( \cfrac{b+2a}{c} \right)^2\implies \cfrac{(b+2a)^2}{c^2} \\\\[-0.35em] ~\dotfill\\\\ ~\hfill \cfrac{b^2+4ab+4a^2}{c^2}~\hfill$