-12000-300x+x^2=0

Solution for -12000-300x+x^2=0 equation:

-12000-300x+x^2=0

a = 1; b = -300; c = -12000;
Δ = b2-4ac
Δ = -3002-4·1·(-12000)
Δ = 138000
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:

$\sqrt{\Delta}=\sqrt{138000}=\sqrt{400*345}=\sqrt{400}*\sqrt{345}=20\sqrt{345}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-300)-20\sqrt{345}}{2*1}=\frac{300-20\sqrt{345}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-300)+20\sqrt{345}}{2*1}=\frac{300+20\sqrt{345}}{2}
$