(5x-2)(2x+8)=360

Solution for (5x-2)(2x+8)=360 equation:

(5x-2)(2x+8)=360

We move all terms to the left:

(5x-2)(2x+8)-(360)=0

We multiply parentheses ..

(+10x^2+40x-4x-16)-360=0

We get rid of parentheses

10x^2+40x-4x-16-360=0

We add all the numbers together, and all the variables

10x^2+36x-376=0

a = 10; b = 36; c = -376;
Δ = b2-4ac
Δ = 362-4·10·(-376)
Δ = 16336
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{16336}=\sqrt{16*1021}=\sqrt{16}*\sqrt{1021}=4\sqrt{1021}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(36)-4\sqrt{1021}}{2*10}=\frac{-36-4\sqrt{1021}}{20}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(36)+4\sqrt{1021}}{2*10}=\frac{-36+4\sqrt{1021}}{20}
$