For this derivative, you want to break it into 2 separate pieces -- whenever you are adding or subtracting you can take the derivatives separately. Just remember to add them together at the end!
d/dx e6x^2 + d/dx 8x
The derivative of eanything is just itself * the derivative of the inside function (chain rule).
d/dx e6x^2 = e6x^2 * (12x)
d/dx 8x = 8
so adding these together you get:
12xe6x^2 + 8
Hope this helps!