2n(-5n-6)=0

Solution for 2n(-5n-6)=0 equation:

2n(-5n-6)=0

We multiply parentheses

-10n^2-12n=0

a = -10; b = -12; c = 0;
Δ = b2-4ac
Δ = -122-4·(-10)·0
Δ = 144
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{144}=12$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-12)-12}{2*-10}=\frac{0}{-20}
=0
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12)+12}{2*-10}=\frac{24}{-20}
=-1+1/5
$