Use the method of undetermined coefficients to solve the following differential equation: $$y'' + 6y' + 9y = 2 e^{-x}$$ Answer: $y(x) =$ $+ C_{1}$ $+ C_{2}$ .
NOTE: The order of your answers is important in this problem. For example, webwork may expect the answer "A+B" but the answer you give is "B+A". Both answers are correct but webwork will only accept the former.