0=1500-320x+12x2

Solution for 0=1500-320x+12x2 equation:

0=1500-320x+12x^2

We move all terms to the left:

0-(1500-320x+12x^2)=0

We add all the numbers together, and all the variables

-(1500-320x+12x^2)=0

We get rid of parentheses

-12x^2+320x-1500=0

a = -12; b = 320; c = -1500;
Δ = b2-4ac
Δ = 3202-4·(-12)·(-1500)
Δ = 30400
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:

$\sqrt{\Delta}=\sqrt{30400}=\sqrt{1600*19}=\sqrt{1600}*\sqrt{19}=40\sqrt{19}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(320)-40\sqrt{19}}{2*-12}=\frac{-320-40\sqrt{19}}{-24}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(320)+40\sqrt{19}}{2*-12}=\frac{-320+40\sqrt{19}}{-24}
$