353=-5x+4.905x^2

Solution for 353=-5x+4.905x^2 equation:

353=-5x+4.905x^2

We move all terms to the left:

353-(-5x+4.905x^2)=0

We get rid of parentheses

-4.905x^2+5x+353=0

a = -4.905; b = 5; c = +353;
Δ = b2-4ac
Δ = 52-4·(-4.905)·353
Δ = 6950.86
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(5)-\sqrt{6950.86}}{2*-4.905}=\frac{-5-\sqrt{6950.86}}{-9.81}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(5)+\sqrt{6950.86}}{2*-4.905}=\frac{-5+\sqrt{6950.86}}{-9.81}
$