n(n-1-)(n-2)=336

Solution for n(n-1-)(n-2)=336 equation:

n(n-1-)(n-2)=336

We move all terms to the left:

n(n-1-)(n-2)-(336)=0

We add all the numbers together, and all the variables

nn(n-2)-336=0

We multiply parentheses

n^2-2n-336=0

a = 1; b = -2; c = -336;
Δ = b2-4ac
Δ = -22-4·1·(-336)
Δ = 1348
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1348}=\sqrt{4*337}=\sqrt{4}*\sqrt{337}=2\sqrt{337}$
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-2\sqrt{337}}{2*1}=\frac{2-2\sqrt{337}}{2}
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+2\sqrt{337}}{2*1}=\frac{2+2\sqrt{337}}{2}
$