Can PDE tool box solve first order PDE s

I have a system of PDEs and two of them are second order and one of them is first order. Matlab PDE toolbox has a specific format which allows only second order PDEs. How can I use PDE tool box to solve the system of first order, and second order PDEs.

[Peter Cook]

I can't see your PDEs, but if you have just a single spatial dimension you should be able to rewrite the system as coupled ODEs.

Again I cant see your equations, but I think that as long as at least one of the equations in the system has a nonzero laplacian then pde toolbox should work. You'll need to define your coefficient functions appropriately (c,a,f&d, c in this case will be zero for the first order PDE).