2640=-16t^2+256t+1680

Solution for 2640=-16t^2+256t+1680 equation:

2640=-16t^2+256t+1680

We move all terms to the left:

2640-(-16t^2+256t+1680)=0

We get rid of parentheses

16t^2-256t-1680+2640=0

We add all the numbers together, and all the variables

16t^2-256t+960=0

a = 16; b = -256; c = +960;
Δ = b2-4ac
Δ = -2562-4·16·960
Δ = 4096
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4096}=64$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-256)-64}{2*16}=\frac{192}{32}
=6
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-256)+64}{2*16}=\frac{320}{32}
=10
$