x^2-20x=156

Solution for x^2-20x=156 equation:

x^2-20x=156

We move all terms to the left:

x^2-20x-(156)=0

a = 1; b = -20; c = -156;
Δ = b2-4ac
Δ = -202-4·1·(-156)
Δ = 1024
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1024}=32$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-20)-32}{2*1}=\frac{-12}{2}
=-6
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-20)+32}{2*1}=\frac{52}{2}
=26
$