(2x-2)(x+5)90=180

Solution for (2x-2)(x+5)90=180 equation:

(2x-2)(x+5)90=180

We move all terms to the left:

(2x-2)(x+5)90-(180)=0

We multiply parentheses ..

(+2x^2+10x-2x-10)90-180=0

We multiply parentheses

180x^2+900x-180x-900-180=0

We add all the numbers together, and all the variables

180x^2+720x-1080=0

a = 180; b = 720; c = -1080;
Δ = b2-4ac
Δ = 7202-4·180·(-1080)
Δ = 1296000
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:

$\sqrt{\Delta}=\sqrt{1296000}=\sqrt{129600*10}=\sqrt{129600}*\sqrt{10}=360\sqrt{10}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(720)-360\sqrt{10}}{2*180}=\frac{-720-360\sqrt{10}}{360}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(720)+360\sqrt{10}}{2*180}=\frac{-720+360\sqrt{10}}{360}
$