Solve $3y' + 6xy = 6e^{-x}$ where $y(0)=1$.
Based on the reformulation of the given problem, we can proceed as follows in order to solve it: \begin{align*} 3y' + 6xy = 6e^{-x^{2}} & \Longleftrightarrow y' + 2xy = 2e^{-x^{2}}\\\\ & \Longleftrightarrow e^{x^{2}}y' + 2xe^{x^{2}}y = 2\\\\ & \Longleftrightarrow (e^{x^{2}}y)' = 2\\\\ & \Longleftrightarrow e^{x^{2}}y = 2x +c\\\\ & \Longleftrightarrow y(x) = 2xe^{-x^{2}} + ce^{-x^{2}} \end{align*}
Hopefully this helps !