20x^2-x-99=0

Solution for 20x^2-x-99=0 equation:

20x^2-x-99=0

We add all the numbers together, and all the variables

20x^2-1x-99=0

a = 20; b = -1; c = -99;
Δ = b2-4ac
Δ = -12-4·20·(-99)
Δ = 7921
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{7921}=89$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-89}{2*20}=\frac{-88}{40}
=-2+1/5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+89}{2*20}=\frac{90}{40}
=2+1/4
$