-s^2-25s+100=0

Solution for -s^2-25s+100=0 equation:

-s^2-25s+100=0

We add all the numbers together, and all the variables

-1s^2-25s+100=0

a = -1; b = -25; c = +100;
Δ = b2-4ac
Δ = -252-4·(-1)·100
Δ = 1025
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1025}=\sqrt{25*41}=\sqrt{25}*\sqrt{41}=5\sqrt{41}$
$s_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-25)-5\sqrt{41}}{2*-1}=\frac{25-5\sqrt{41}}{-2}
$
$s_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-25)+5\sqrt{41}}{2*-1}=\frac{25+5\sqrt{41}}{-2}
$