4.9t^2+2.0t-45=0

Solution for 4.9t^2+2.0t-45=0 equation:

4.9t^2+2.0t-45=0

a = 4.9; b = 2.0; c = -45;
Δ = b2-4ac
Δ = 2.02-4·4.9·(-45)
Δ = 886
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{886}=\sqrt{1*886}=\sqrt{1}*\sqrt{886}=1\sqrt{886}$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2.0)-1\sqrt{886}}{2*4.9}=\frac{-2-1\sqrt{886}}{9.8}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2.0)+1\sqrt{886}}{2*4.9}=\frac{-2+1\sqrt{886}}{9.8}
$