1. As far as sketching , this is simply a right shift of . You'll need a few points on the graph to help you sketch it. The root is indeed 2. What is y when x = 0?
2. Zero is not a root of , because x = 0 gives y = 125. The roots are dependent on the polynomial factors of x + 5 and x - 5, not the multiple of -5.
3. In your equation the negative sign is not ignored. You can distribute it across to yield the equation . Additionally, this graph is not a parabola. When I write it in this form, can you see why?