-x^2-61x-900=0

Solution for -x^2-61x-900=0 equation:

-x^2-61x-900=0

We add all the numbers together, and all the variables

-1x^2-61x-900=0

a = -1; b = -61; c = -900;
Δ = b2-4ac
Δ = -612-4·(-1)·(-900)
Δ = 121
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{121}=11$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-61)-11}{2*-1}=\frac{50}{-2}
=-25
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-61)+11}{2*-1}=\frac{72}{-2}
=-36
$