What is the Derivative of a Cubic Function with a Given Value of x?

[b521]

Homework Statement

If y = x³ + 2x
and
dx/dt = 5,
find
dy/dt when x = 2.

The Attempt at a Solution

I'm not really sure how to solve this problem at all. It's the first I've seen like this so I don't know what approach I should take.

 

[hunt_mat]

Use the chain rule in the form:
<br /> \frac{dy}{dt}=\frac{dy}{dx}\frac{dx}{dt}<br />

 

[b521]

Thank you so much!