20n=25n^2

Solution for 20n=25n^2 equation:

20n=25n^2

We move all terms to the left:

20n-(25n^2)=0

determiningTheFunctionDomain
-25n^2+20n=0

a = -25; b = 20; c = 0;
Δ = b2-4ac
Δ = 202-4·(-25)·0
Δ = 400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{400}=20$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(20)-20}{2*-25}=\frac{-40}{-50}
=4/5
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+20}{2*-25}=\frac{0}{-50}
=0
$