(x+18)(x)=360

Solution for (x+18)(x)=360 equation:

(x+18)(x)=360

We move all terms to the left:

(x+18)(x)-(360)=0

We multiply parentheses

x^2+18x-360=0

a = 1; b = 18; c = -360;
Δ = b2-4ac
Δ = 182-4·1·(-360)
Δ = 1764
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1764}=42$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(18)-42}{2*1}=\frac{-60}{2}
=-30
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(18)+42}{2*1}=\frac{24}{2}
=12
$