-100x=25x^2

Solution for -100x=25x^2 equation:

-100x=25x^2

We move all terms to the left:

-100x-(25x^2)=0

determiningTheFunctionDomain
-25x^2-100x=0

a = -25; b = -100; c = 0;
Δ = b2-4ac
Δ = -1002-4·(-25)·0
Δ = 10000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{10000}=100$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-100)-100}{2*-25}=\frac{0}{-50}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-100)+100}{2*-25}=\frac{200}{-50}
=-4
$