Apply the method of undetermined coefficients to find a particular solution of each of the systems. Primes denote derivatives with respect to $\displaystyle t$.

1) $\displaystyle x'=x+y+2t,\ y'=x+y-2t$

2) $\displaystyle x'=2x+y+1,\ y'=3x+2y+e^{4t}$