80=-16t^2+8t+80

Solution for 80=-16t^2+8t+80 equation:

80=-16t^2+8t+80

We move all terms to the left:

80-(-16t^2+8t+80)=0

We get rid of parentheses

16t^2-8t-80+80=0

We add all the numbers together, and all the variables

16t^2-8t=0

a = 16; b = -8; c = 0;
Δ = b2-4ac
Δ = -82-4·16·0
Δ = 64
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{64}=8$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-8)-8}{2*16}=\frac{0}{32}
=0
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8)+8}{2*16}=\frac{16}{32}
=1/2
$