-4.9x^2-8x+450=0

Solution for -4.9x^2-8x+450=0 equation:

-4.9x^2-8x+450=0

a = -4.9; b = -8; c = +450;
Δ = b2-4ac
Δ = -82-4·(-4.9)·450
Δ = 8884
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{8884}=\sqrt{4*2221}=\sqrt{4}*\sqrt{2221}=2\sqrt{2221}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-8)-2\sqrt{2221}}{2*-4.9}=\frac{8-2\sqrt{2221}}{-9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8)+2\sqrt{2221}}{2*-4.9}=\frac{8+2\sqrt{2221}}{-9.8}
$