360=(5x-10)(3x+10)

Solution for 360=(5x-10)(3x+10) equation:

360=(5x-10)(3x+10)

We move all terms to the left:

360-((5x-10)(3x+10))=0

We multiply parentheses ..

-((+15x^2+50x-30x-100))+360=0


We calculate terms in parentheses: -((+15x^2+50x-30x-100)), so:

(+15x^2+50x-30x-100)

We get rid of parentheses

15x^2+50x-30x-100

We add all the numbers together, and all the variables

15x^2+20x-100

Back to the equation:

-(15x^2+20x-100)


We get rid of parentheses

-15x^2-20x+100+360=0

We add all the numbers together, and all the variables

-15x^2-20x+460=0

a = -15; b = -20; c = +460;
Δ = b2-4ac
Δ = -202-4·(-15)·460
Δ = 28000
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:

$\sqrt{\Delta}=\sqrt{28000}=\sqrt{400*70}=\sqrt{400}*\sqrt{70}=20\sqrt{70}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-20)-20\sqrt{70}}{2*-15}=\frac{20-20\sqrt{70}}{-30}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-20)+20\sqrt{70}}{2*-15}=\frac{20+20\sqrt{70}}{-30}
$