ive been given a differential equation:

(d2y/dx2)-3(dy/dx)+2y=xe^2x

and cannot work out the particular solution. i have tried

$\displaystyle y=Ax^{2} e^{x}$

getting my y' as $\displaystyle 2Cxe^{x} + Cx^{2}e^{x}$

and y'' as $\displaystyle Cx^{2}e^{x} + 4Cxe^{x} + 2Ce^{x}$

but then end up getting 2C=0

is this question impossible or have i used the wrong particular solution and if so how would i go about it?

HELP!!