Let's find the derivative:
[tex]\begin{gathered} \frac{dy}{dx}=\frac{d}{dx}(6xe^x-6e^x) \\ =6\frac{d}{dx}(xe^x)-6\frac{d}{dx}e^x \\ =6\lbrack x\frac{d}{dx}e^x+e^x\frac{d}{dx}x\rbrack-6e^x \\ =6(xe^x+e^x)-6e^x \\ =6xe^x+6e^x-6e^x \\ =6xe^x \end{gathered}[/tex]Therefore:
[tex]\frac{dy}{dx}=6xe^x[/tex]