Solution (source code)

= Solution

The <characteristic equation> for the <homogeneous solution> is $(r+2)^2=0$, giving $(C_1+C_2x)e^{-2x}$. For a <particular solution>, substitute $Ae^{2x}$: the left side becomes $16Ae^{2x}$, so $A=1/16$. The <general solution> is
$$
\boxed{y=(C_1+C_2x)e^{-2x}+\frac1{16}e^{2x}.}
$$