350=12x(x+20)

Solution for 350=12x(x+20) equation:

350=12x(x+20)

We move all terms to the left:

350-(12x(x+20))=0


We calculate terms in parentheses: -(12x(x+20)), so:

12x(x+20)

We multiply parentheses

12x^2+240x

Back to the equation:

-(12x^2+240x)


We get rid of parentheses

-12x^2-240x+350=0

a = -12; b = -240; c = +350;
Δ = b2-4ac
Δ = -2402-4·(-12)·350
Δ = 74400
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:

$\sqrt{\Delta}=\sqrt{74400}=\sqrt{400*186}=\sqrt{400}*\sqrt{186}=20\sqrt{186}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-240)-20\sqrt{186}}{2*-12}=\frac{240-20\sqrt{186}}{-24}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-240)+20\sqrt{186}}{2*-12}=\frac{240+20\sqrt{186}}{-24}
$