Limit of h goes to 0 $\displaystyle [2(x+h)^2+5(x+h)^4]-[2x^2+5x^4]/h=?$

(Hint: This is the definition of the derivative.)

Obviously the hint is giving me a big clue, but I don't understand the concept. My limits are kinda rusty, and I'm not sure what to do. Help Please.