1. ## Diff eq

for some reason i am having trouble doing this problem and i think it is really easy:

dy/dx=x+3y

I just don't see what to do can someone help me? thanks

2. Originally Posted by jarny
for some reason i am having trouble doing this problem and i think it is really easy:

dy/dx=x+3y

I just don't see what to do can someone help me? thanks
This is the same as $\frac{\,dy}{\,dx}-3y=x$

This is a linear DE, and the integrating factor is $\varrho\!\left(x\right)=e^{\int 3\,dx}=e^{3x}$

Thus, we now see that $\frac{\,d}{\,dx}\left[ye^{3x}\right]=xe^{3x}$.

Now, integrating both sides yields $ye^{3x}=\int xe^{3x}\,dx$

Can you continue on from here?