(2x+20)(2x+8)=540

Solution for (2x+20)(2x+8)=540 equation:

(2x+20)(2x+8)=540

We move all terms to the left:

(2x+20)(2x+8)-(540)=0

We multiply parentheses ..

(+4x^2+16x+40x+160)-540=0

We get rid of parentheses

4x^2+16x+40x+160-540=0

We add all the numbers together, and all the variables

4x^2+56x-380=0

a = 4; b = 56; c = -380;
Δ = b2-4ac
Δ = 562-4·4·(-380)
Δ = 9216
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{9216}=96$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(56)-96}{2*4}=\frac{-152}{8}
=-19
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(56)+96}{2*4}=\frac{40}{8}
=5
$