7. x=3 is the midpoint between the roots. The other root is x = 2*3 -(-5) = 11.
8a) f(x) = (x +3)^2 -49. The vertex is (-3, -49). The roots are -10, 4.
8b) y = (x+4)^2 -1. The vertex is (-4, -1). The roots are -5, -3.
8c) f(x) = 2(x +3)^2 -34. The vertex is (-3, -34). The roots are -3±√17.
