Find derivatives of functions

[Mathamateur]

Alright, I have two questions. The first I think I have right, but I just want to make sure. The 2nd I have little or no clue on. Anyways, thanks in advance for the help.

Use the rules for derivatives to find the derivative of each function defined as follows

1.) y = 8e^5x

I came up with dy/dx = 40^5x by simply multiplying 8 by 5 eliminating the e and keeping the exponent. This appeared to be the process based on an example problem I looked at. Am I right...close...or way off?

2nd problem is from another section and I am lost

Find the derivative of each function defined as follows

2.) y = (2x^3 + 9x)^5

 

[skeeter]

do you know the chain rule for derivatives?

if k is a constant and u is a function of x ...

\(\displaystyle \L \frac{d}{dx}[ke^u] = ke^u \cdot \frac{du}{dx}\)


if u is a function of x ...

\(\displaystyle \L \frac{d}{dx}[u^n] = nu^{n-1} \cdot \frac{du}{dx}\)

 

[Mathamateur]

I somewhat understand it, how would the numbers be plugged into it though for these two problems and how would you solve it from there? Am I right on the 1st one?

 

[Mathamateur]

Can someone PLEASE help?