H=1600-16t^2

Solution for H=1600-16t^2 equation:

=1600-16H^2

We move all terms to the left:

-(1600-16H^2)=0

We get rid of parentheses

16H^2-1600=0

a = 16; b = 0; c = -1600;
Δ = b2-4ac
Δ = 02-4·16·(-1600)
Δ = 102400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$H_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$H_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{102400}=320$
$H_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-320}{2*16}=\frac{-320}{32}
=-10
$
$H_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+320}{2*16}=\frac{320}{32}
=10
$