5e^.2x=7
ln(5e^.2x) = ln7
is
$\displaystyle
\frac{x}{5} + ln5 = ln7
$
so $\displaystyle x = 5(ln7 - ln5)$ or $\displaystyle 5ln\frac{7}{5}$
use latex to get the power
x^2 then highlight the expression with $\displaystyle \Sigma $icon and you get $\displaystyle x^2$ after it is compiled in preview or after saving and posting