I am stuck with the following problem.
I know how to solve the following partial differential equation $$\frac{\partial u(x,t)}{\partial t} +A(x,t) \frac{\partial^2 u(x,t)}{\partial^2 x}+ B(x,t) \frac{\partial u(x,t)}{\partial x} - Cu(x,t)=0,$$ if $A(x,t)=A$ and $B(x,t)=B$ are constants for all $(x,t)$ and I have some boundary conditions (note that $C$ is also a constant).
However, what if $A$ and $B$ are variable (i.e. they are functions of $x$ and $t$)? What is then the correct approach to solve this PDE with variable coefficients?