99+2x=x2

Solution for 99+2x=x2 equation:

99+2x=x2

We move all terms to the left:

99+2x-(x2)=0

We add all the numbers together, and all the variables

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

a = -1; b = 2; c = +99;
Δ = b2-4ac
Δ = 22-4·(-1)·99
Δ = 400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{400}=20$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-20}{2*-1}=\frac{-22}{-2}
=+11
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+20}{2*-1}=\frac{18}{-2}
=-9
$