Answer
$x=\dfrac{\log5.6}{3\log5}\approx0.3568$
Work Step by Step
$5^{3x}=5.6$
Apply $\log$ to both sides of the equation:
$\log5^{3x}=\log5.6$
Take $3x$ down to multiply in front of its respective $\log$:
$3x\log5=\log5.6$
Solve for $x$:
$3x=\dfrac{\log5.6}{\log5}$
$x=\dfrac{\log5.6}{3\log5}\approx0.3568$
