49. Correct. The answer is false. To solve ∫3xe^xdx let f(x) = 2x and g'(x) = e^x, then f'(x) = 2 and g(x) = e^x. Then ∫3xe^xdx = 3xe^x - ∫3e^xdx = 3xe^x - 3e^x + c