X^2-2x=136

Solution for X^2-2x=136 equation:

X^2-2X=136

We move all terms to the left:

X^2-2X-(136)=0

a = 1; b = -2; c = -136;
Δ = b2-4ac
Δ = -22-4·1·(-136)
Δ = 548
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:

$\sqrt{\Delta}=\sqrt{548}=\sqrt{4*137}=\sqrt{4}*\sqrt{137}=2\sqrt{137}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-2\sqrt{137}}{2*1}=\frac{2-2\sqrt{137}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+2\sqrt{137}}{2*1}=\frac{2+2\sqrt{137}}{2}
$