Answer
$x \approx 10.11$
Work Step by Step
Add $1.4^x$ on both sides of the equation to obtain:
$30=^x$
RECALL:
$\log_b{a^x} = x \cdot \log_b{a}$
Take the natural logarithm of both sides to obtain:
$\ln{30}=\ln{(1.4^x)}$
Use the rule above to obtain:
$\ln{30}=x \cdot \ln{(1.4)}$
Divide both sides by $\ln{(1.4)}$ to obtain:
$\dfrac{\ln{30}}{\ln1.4}=x$
Use a scientific calculator to obtain:
$10.10840424 = x
\\x \approx 10.11$