-5x^2-90x=-555

Solution for -5x^2-90x=-555 equation:

-5x^2-90x=-555

We move all terms to the left:

-5x^2-90x-(-555)=0

We add all the numbers together, and all the variables

-5x^2-90x+555=0

a = -5; b = -90; c = +555;
Δ = b2-4ac
Δ = -902-4·(-5)·555
Δ = 19200
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:

$\sqrt{\Delta}=\sqrt{19200}=\sqrt{6400*3}=\sqrt{6400}*\sqrt{3}=80\sqrt{3}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-90)-80\sqrt{3}}{2*-5}=\frac{90-80\sqrt{3}}{-10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-90)+80\sqrt{3}}{2*-5}=\frac{90+80\sqrt{3}}{-10}
$