-8t^2+60t+200=0

Solution for -8t^2+60t+200=0 equation:

-8t^2+60t+200=0

a = -8; b = 60; c = +200;
Δ = b2-4ac
Δ = 602-4·(-8)·200
Δ = 10000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{10000}=100$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(60)-100}{2*-8}=\frac{-160}{-16}
=+10
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(60)+100}{2*-8}=\frac{40}{-16}
=-2+1/2
$