Answer
a) $$\ln1600$$
b) $$\ln({9x^{7/2}})$$
Work Step by Step
a) $2\ln5+3\ln4$
$=\ln{5^2}+\ln{4^3}$
$=\ln25+\ln64$
$=\ln({25\times64})$
$= \ln1600$
b) $5\ln{(x^{1/2})}+\ln{9x}$
$=\ln(x^{5/2})+\ln{9x}$
$=\ln{(x^{5/2} \times 9x)}$
$=\ln({9x^{7/2}})$
