(2x-4)(4x-30)=360

Solution for (2x-4)(4x-30)=360 equation:

(2x-4)(4x-30)=360

We move all terms to the left:

(2x-4)(4x-30)-(360)=0

We multiply parentheses ..

(+8x^2-60x-16x+120)-360=0

We get rid of parentheses

8x^2-60x-16x+120-360=0

We add all the numbers together, and all the variables

8x^2-76x-240=0

a = 8; b = -76; c = -240;
Δ = b2-4ac
Δ = -762-4·8·(-240)
Δ = 13456
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{13456}=116$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-76)-116}{2*8}=\frac{-40}{16}
=-2+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-76)+116}{2*8}=\frac{192}{16}
=12
$