480=16t+16t^2

Solution for 480=16t+16t^2 equation:

480=16t+16t^2

We move all terms to the left:

480-(16t+16t^2)=0

We get rid of parentheses

-16t^2-16t+480=0

a = -16; b = -16; c = +480;
Δ = b2-4ac
Δ = -162-4·(-16)·480
Δ = 30976
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{30976}=176$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-16)-176}{2*-16}=\frac{-160}{-32}
=+5
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+176}{2*-16}=\frac{192}{-32}
=-6
$