H=-14t^2+56t+60

Solution for H=-14t^2+56t+60 equation:

=-14H^2+56H+60

We move all terms to the left:

-(-14H^2+56H+60)=0

We get rid of parentheses

14H^2-56H-60=0

a = 14; b = -56; c = -60;
Δ = b2-4ac
Δ = -562-4·14·(-60)
Δ = 6496
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$H_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$H_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{6496}=\sqrt{16*406}=\sqrt{16}*\sqrt{406}=4\sqrt{406}$
$H_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-56)-4\sqrt{406}}{2*14}=\frac{56-4\sqrt{406}}{28}
$
$H_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-56)+4\sqrt{406}}{2*14}=\frac{56+4\sqrt{406}}{28}
$