118=x^2-2x

Solution for 118=x^2-2x equation:

118=x^2-2x

We move all terms to the left:

118-(x^2-2x)=0

We get rid of parentheses

-x^2+2x+118=0

We add all the numbers together, and all the variables

-1x^2+2x+118=0

a = -1; b = 2; c = +118;
Δ = b2-4ac
Δ = 22-4·(-1)·118
Δ = 476
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:

$\sqrt{\Delta}=\sqrt{476}=\sqrt{4*119}=\sqrt{4}*\sqrt{119}=2\sqrt{119}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-2\sqrt{119}}{2*-1}=\frac{-2-2\sqrt{119}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+2\sqrt{119}}{2*-1}=\frac{-2+2\sqrt{119}}{-2}
$