-4.8=2.33t-4.9t^2

Solution for -4.8=2.33t-4.9t^2 equation:

-4.8=2.33t-4.9t^2

We move all terms to the left:

-4.8-(2.33t-4.9t^2)=0

We get rid of parentheses

4.9t^2-2.33t-4.8=0

a = 4.9; b = -2.33; c = -4.8;
Δ = b2-4ac
Δ = -2.332-4·4.9·(-4.8)
Δ = 99.5089
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{-(-2.33)-\sqrt{99.5089}}{2*4.9}=\frac{2.33-\sqrt{99.5089}}{9.8}
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2.33)+\sqrt{99.5089}}{2*4.9}=\frac{2.33+\sqrt{99.5089}}{9.8}
$