Answer
$x = \dfrac{\log{5.6}}{3\log{5}}x \approx 0.3568$
Work Step by Step
Take the common logarithm of both sides to have:
$\log{5^{3x}}=\log{5.6}$
Apply the power property of logarithms to have:
$3x(\log{5}) = \log{5.6}$
Divide $3\log{5}$ to both sides to have:
$\\x = \dfrac{\log{5.6}}{3\log{5}}
\\x \approx 0.3568$
