You know Abia, I think a good idea is to use what Data said and consider under what conditions will the graph:
[tex]y(x)=e^{\alpha x-\gamma}[/tex]
cross the line y=x, you know, when that expression "equals" x. Where they touch is where the solutions are if any. It's getting off the subject I know but it helps to do things like this for practice for future problems right? You know how he got that expression and what alpha and gamma are? Know how alpha and gamma are related to a,b, and c? However, you may not want to do "investigative" work like this. I like to.