0=4t+4.9t^2-5

Solution for 0=4t+4.9t^2-5 equation:

0=4t+4.9t^2-5

We move all terms to the left:

0-(4t+4.9t^2-5)=0

We add all the numbers together, and all the variables

-(4t+4.9t^2-5)=0

We get rid of parentheses

-4.9t^2-4t+5=0

a = -4.9; b = -4; c = +5;
Δ = b2-4ac
Δ = -42-4·(-4.9)·5
Δ = 114
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{-(-4)-\sqrt{114}}{2*-4.9}=\frac{4-\sqrt{114}}{-9.8}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4)+\sqrt{114}}{2*-4.9}=\frac{4+\sqrt{114}}{-9.8}
$