(-x^2)+99x-99=0

Solution for (-x^2)+99x-99=0 equation:

(-x^2)+99x-99=0

We get rid of parentheses

-x^2+99x-99=0

We add all the numbers together, and all the variables

-1x^2+99x-99=0

a = -1; b = 99; c = -99;
Δ = b2-4ac
Δ = 992-4·(-1)·(-99)
Δ = 9405
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:

$\sqrt{\Delta}=\sqrt{9405}=\sqrt{9*1045}=\sqrt{9}*\sqrt{1045}=3\sqrt{1045}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(99)-3\sqrt{1045}}{2*-1}=\frac{-99-3\sqrt{1045}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(99)+3\sqrt{1045}}{2*-1}=\frac{-99+3\sqrt{1045}}{-2}
$