-168=-x2+2x

Solution for -168=-x2+2x equation:

-168=-x2+2x

We move all terms to the left:

-168-(-x2+2x)=0

We add all the numbers together, and all the variables

-(-1x^2+2x)-168=0

We get rid of parentheses

1x^2-2x-168=0

We add all the numbers together, and all the variables

x^2-2x-168=0

a = 1; b = -2; c = -168;
Δ = b2-4ac
Δ = -22-4·1·(-168)
Δ = 676
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{676}=26$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-26}{2*1}=\frac{-24}{2}
=-12
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+26}{2*1}=\frac{28}{2}
=14
$