What formula can represent ax-bx+y=0

The way you have written it now it is just a straight line. It is a bit weird that you have a and b, since you can rewrite as (a-b)x+y = 0, which shows that a-b is the constant that determines the slope of the line.

I suspect that you may have intended ax^2-bx+y=0. That is a parabola. But maybe not, and then it's just a straight line.

Your line will always pass through the origin (0,0). Regardless of a and b, you can easily (I hope) see that it will. 

What is the question really asking? 

As you know john locke said he wanted life liberty and the pursuit of happiness so thomas jefferson was inspired about what john locke said so thomas jefferson wrote the declaration of independence for people to be free for people to be happy