-13x^2-25x=0

Solution for -13x^2-25x=0 equation:

-13x^2-25x=0

a = -13; b = -25; c = 0;
Δ = b2-4ac
Δ = -252-4·(-13)·0
Δ = 625
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{625}=25$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-25)-25}{2*-13}=\frac{0}{-26}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-25)+25}{2*-13}=\frac{50}{-26}
=-1+12/13
$