a). Zeros are at x = 1 and 5.
Multiplicity of each is one.
b). at x=1 and x = 5 is where y = 0
c). f'(x) - 0 at turning points (maxima or minima). That occurs when 2x = 6
x = 3.
d). For very large |x| (positive or negating x), f(x) increases as a parabola upward to infinity.