3+25.5t-4.9t^2=0

Solution for 3+25.5t-4.9t^2=0 equation:

3+25.5t-4.9t^2=0

a = -4.9; b = 25.5; c = +3;
Δ = b2-4ac
Δ = 25.52-4·(-4.9)·3
Δ = 709.05
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{-(25.5)-\sqrt{709.05}}{2*-4.9}=\frac{-25.5-\sqrt{709.05}}{-9.8}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(25.5)+\sqrt{709.05}}{2*-4.9}=\frac{-25.5+\sqrt{709.05}}{-9.8}
$