#### Answer

fill the blank with $\ln 5$

#### Work Step by Step

Apply the basic property of logarithms:
$ b^{\log_{b}x}=x\qquad$ with base b=e, and substitute x with $5^x$:
$5^{x}=e^{\ln 5^{x}}$
$....$and now, apply the The Power Rule:
$\log_{\mathrm{b}}\mathrm{M}^{\mathrm{p}}=\mathrm{p}\log_{\mathrm{b}}\mathrm{M}$
$5^{x}=e^{(\ln 5)\cdot x}$
So
$y=3\cdot e^{(\ln 5)\cdot x}$
fill the blank with $\ln 5$