I'm looking to purchase a laptop. I'll be using it as a portable means of using MatLab and doing some projects with Python and C and any other language I feel like learning at the time. Budget is 500 dollars. If I can get away with less I'd do it though. Less than 15 inches is preferred, I'm from the USA, and OS doesn't matter because I'll be putting Ubuntu on it anyways. Recommendations, gives them to me!