4.905t^2-124.36t-130=0

Solution for 4.905t^2-124.36t-130=0 equation:

4.905t^2-124.36t-130=0

a = 4.905; b = -124.36; c = -130;
Δ = b2-4ac
Δ = -124.362-4·4.905·(-130)
Δ = 18016.0096
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-124.36)-\sqrt{18016.0096}}{2*4.905}=\frac{124.36-\sqrt{18016.0096}}{9.81}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-124.36)+\sqrt{18016.0096}}{2*4.905}=\frac{124.36+\sqrt{18016.0096}}{9.81}
$