tstory28 0 Light Poster

I already understand how to do the quadratic equation when the it is in the format of ax^2 + bx + c and the a variable is 1. The only problem I am having to make it a fully functional quadratic equation solver, it needs to work with a being 2, 3, 4, etc. Can someone explain how to change the equation to work with the a variable being 2+.

Thanks for any help in advance.