20=-16t^2+40t+44

Solution for 20=-16t^2+40t+44 equation:

20=-16t^2+40t+44

We move all terms to the left:

20-(-16t^2+40t+44)=0

We get rid of parentheses

16t^2-40t-44+20=0

We add all the numbers together, and all the variables

16t^2-40t-24=0

a = 16; b = -40; c = -24;
Δ = b2-4ac
Δ = -402-4·16·(-24)
Δ = 3136
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3136}=56$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-40)-56}{2*16}=\frac{-16}{32}
=-1/2
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-40)+56}{2*16}=\frac{96}{32}
=3
$