-6n(5n-10)=0

Solution for -6n(5n-10)=0 equation:

-6n(5n-10)=0

We multiply parentheses

-30n^2+60n=0

a = -30; b = 60; c = 0;
Δ = b2-4ac
Δ = 602-4·(-30)·0
Δ = 3600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3600}=60$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(60)-60}{2*-30}=\frac{-120}{-60}
=+2
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(60)+60}{2*-30}=\frac{0}{-60}
=0
$