Can anyone help?

Question

The equation h=-16t^2+112t gives the height of an
arrow, shot upward from the ground with an initial velocity of 112 ft/s, where t is the time after the arrow leaves the ground. Find the time it takes for the arrow to reach a height of 180 ft.

Answer 1

Substitute 180 for h in formula.
180 = -16t^2 + 112t
Restate in normal form:
16t^2 - 112t + 180 = 0
Factor into a binomial:
(4t - 18)(4t - 10) = 0
Assume one factor = 0
4t = 18 or 4t = 10
Therefore t = 4.5secs or t = 2.5secs
The arrow will reach 180 feet in 2.5 seconds,
and again in 4.5 seconds, on the way down.