9n-9n-9n+9n*99999n=00

Solution for 9n-9n-9n+9n*99999n=00 equation:

9n-9n-9n+9n*99999n=00

We add all the numbers together, and all the variables

-9n+9n*99999n=0

Wy multiply elements

899991n^2-9n=0

a = 899991; b = -9; c = 0;
Δ = b2-4ac
Δ = -92-4·899991·0
Δ = 81
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{81}=9$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-9)-9}{2*899991}=\frac{0}{1799982}
=0
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-9)+9}{2*899991}=\frac{18}{1799982}
=1/99999
$