0=450-5x-4.9x^2

Solution for 0=450-5x-4.9x^2 equation:

0=450-5x-4.9x^2

We move all terms to the left:

0-(450-5x-4.9x^2)=0

We add all the numbers together, and all the variables

-(450-5x-4.9x^2)=0

We get rid of parentheses

4.9x^2+5x-450=0

a = 4.9; b = 5; c = -450;
Δ = b2-4ac
Δ = 52-4·4.9·(-450)
Δ = 8845
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{8845}}{2*4.9}=\frac{-5-\sqrt{8845}}{9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(5)+\sqrt{8845}}{2*4.9}=\frac{-5+\sqrt{8845}}{9.8}
$