Dear Folks,

Can anyone get me started on how to approach the following question:

Consider the following 1st order linear PDE $\displaystyle a(x,y) \frac{\partial u}{\partial x} + b(x,y) \frac{\partial u}{\partial y} + c(x,y)u=0$

If u and v are 2 solutions shown that a) u + v and b) ku for any constant k are also solutions?

Just a tip would be good, I want to tackle it myself.

Thanks