Help solving Derivatives please?

As a race car accelerated away from the starting line, its velocity at any given time is modeled by this function: V=5t^2+2t
Find the rate at which the car is accelerating after 3 seconds.

So supposedly the answer is 32. The derivative is 10t+2 also. My question is, how do you get the derivative? What I mean is, how do you go from V=5t^2+2t to 10t+2. If you could explain it to me you have no idea how greatfull I will be!!

Question

Help solving Derivatives please? 

As a race car accelerated away from the starting line, its velocity at any given time is modeled by this function: V=5t^2+2t     
Find the rate at which the car is accelerating after 3 seconds.

So supposedly the answer is 32. The derivative is 10t+2 also. My question is, how do you get the derivative? What I mean is, how do you go from V=5t^2+2t to 10t+2. If you could explain it to me you have no idea how greatfull I will be!!