-x^2-85x=0

Solution for -x^2-85x=0 equation:

-x^2-85x=0

We add all the numbers together, and all the variables

-1x^2-85x=0

a = -1; b = -85; c = 0;
Δ = b2-4ac
Δ = -852-4·(-1)·0
Δ = 7225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{7225}=85$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-85)-85}{2*-1}=\frac{0}{-2}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-85)+85}{2*-1}=\frac{170}{-2}
=-85
$