Answer
$5x^{4}$
Work Step by Step
SUMMARY:$\\$
The Power Rule$:\ \ \ [x^{n}]^{\prime}=nx^{n-1 }\\$
Sum Rule: $\ \ \ \ \ \ \ [f\pm g]^{\prime}(x)=f^{\prime}(x)\pm g^{\prime}(x)\\$
Constant Multiple Rule:$\ \ \ [cf]^{\prime}(x)=cf^{\prime}(x)\\$
$\displaystyle \frac{d}{dx}(cx)=c,\ \ \ \ \ \ \frac{d}{dx}(c)=0\\$
--------------------------------
$[x^{5}]^{\prime}$=... Power rule... =$5x^{4}$