(5n+9)*2n=0

Solution for (5n+9)*2n=0 equation:

(5n+9)*2n=0

We multiply parentheses

10n^2+18n=0

a = 10; b = 18; c = 0;
Δ = b2-4ac
Δ = 182-4·10·0
Δ = 324
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{324}=18$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(18)-18}{2*10}=\frac{-36}{20}
=-1+4/5
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(18)+18}{2*10}=\frac{0}{20}
=0
$