How many zeros does this polynomial function, y=(x-8)(x+3)^2

Find the average rate of change for the given function drom x=1 to x=2

The bottom of a slide at the playground is 6 feet from the base of the play set. the length of the slide is 10 feet. how tall is the slide. 11.66 feet 10 feet 6 feet 8 feet

Iknow the answer but the calculator doesn't seem to give the right one