Well what have you tried so far? You know you need to use Laplace Transforms, have you at least tried to take the Laplace Transform of both sides of the equation?
If you are new to it, it's probably a good idea to read your textbook, or whatever you are learning from, to learn the steps to using the Laplace transform for solving differential equations.
Asking us to solve it for you when you have no idea what you are doing isn't going to help you any.