Question 1073707
{{{h=-5t(t-4)}}}
Common factor  {{{-5t}}}.


(b)
Substitute 0, 1, 2, and evaluate each.


(c)
{{{-5t(t-4)=0}}}
{{{t(t-4)=0}}}
roots, 0 and 4.

The ball hits the ground after 4 seconds.


(d)
Maximum h happens at t=2 or   2 seconds.