5n^2-405n=0

Solution for 5n^2-405n=0 equation:

5n^2-405n=0

a = 5; b = -405; c = 0;
Δ = b2-4ac
Δ = -4052-4·5·0
Δ = 164025
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{164025}=405$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-405)-405}{2*5}=\frac{0}{10}
=0
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-405)+405}{2*5}=\frac{810}{10}
=81
$