Ordinary Differential Equations/Non Homogenous 3

Solve

1. $y''-y=e^{-x},x\in \mathbb {R} ,y(0)=y'(0)=0$

Find Particular Integral

1. $y''-7y+12y=24e^{x}$
2. $y''+4y'+4y=e^{-2x}$