136=n(n-1)

Solution for 136=n(n-1) equation:

136=n(n-1)

We move all terms to the left:

136-(n(n-1))=0


We calculate terms in parentheses: -(n(n-1)), so:

n(n-1)

We multiply parentheses

n^2-1n

Back to the equation:

-(n^2-1n)


We get rid of parentheses

-n^2+1n+136=0

We add all the numbers together, and all the variables

-1n^2+n+136=0

a = -1; b = 1; c = +136;
Δ = b2-4ac
Δ = 12-4·(-1)·136
Δ = 545
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$n_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(1)-\sqrt{545}}{2*-1}=\frac{-1-\sqrt{545}}{-2}
$
$n_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1)+\sqrt{545}}{2*-1}=\frac{-1+\sqrt{545}}{-2}
$