-x^2+390x-14000=0

Solution for -x^2+390x-14000=0 equation:

-x^2+390x-14000=0

We add all the numbers together, and all the variables

-1x^2+390x-14000=0

a = -1; b = 390; c = -14000;
Δ = b2-4ac
Δ = 3902-4·(-1)·(-14000)
Δ = 96100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{96100}=310$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(390)-310}{2*-1}=\frac{-700}{-2}
=+350
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(390)+310}{2*-1}=\frac{-80}{-2}
=+40
$