0=-16t^2+56t+72

Solution for 0=-16t^2+56t+72 equation:

0=-16t^2+56t+72

We move all terms to the left:

0-(-16t^2+56t+72)=0

We add all the numbers together, and all the variables

-(-16t^2+56t+72)=0

We get rid of parentheses

16t^2-56t-72=0

a = 16; b = -56; c = -72;
Δ = b2-4ac
Δ = -562-4·16·(-72)
Δ = 7744
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{7744}=88$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-56)-88}{2*16}=\frac{-32}{32}
=-1
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-56)+88}{2*16}=\frac{144}{32}
=4+1/2
$