0=4x^2+380x-6600

Solution for 0=4x^2+380x-6600 equation:

0=4x^2+380x-6600

We move all terms to the left:

0-(4x^2+380x-6600)=0

We add all the numbers together, and all the variables

-(4x^2+380x-6600)=0

We get rid of parentheses

-4x^2-380x+6600=0

a = -4; b = -380; c = +6600;
Δ = b2-4ac
Δ = -3802-4·(-4)·6600
Δ = 250000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{250000}=500$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-380)-500}{2*-4}=\frac{-120}{-8}
=+15
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-380)+500}{2*-4}=\frac{880}{-8}
=-110
$