2x(x-15)=108

Solution for 2x(x-15)=108 equation:

2x(x-15)=108

We move all terms to the left:

2x(x-15)-(108)=0

We multiply parentheses

2x^2-30x-108=0

a = 2; b = -30; c = -108;
Δ = b2-4ac
Δ = -302-4·2·(-108)
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{-(-30)-42}{2*2}=\frac{-12}{4}
=-3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-30)+42}{2*2}=\frac{72}{4}
=18
$