189=(n(n-3))/2

Solution for 189=(n(n-3))/2 equation:

189=(n(n-3))/2

We move all terms to the left:

189-((n(n-3))/2)=0

We multiply all the terms by the denominator


-((n(n-3))+189*2)=0


We calculate terms in parentheses: -((n(n-3))+189*2), so:

(n(n-3))+189*2

We add all the numbers together, and all the variables

(n(n-3))+378


We calculate terms in parentheses: +(n(n-3)), so:

n(n-3)

We multiply parentheses

n^2-3n

Back to the equation:

+(n^2-3n)


We get rid of parentheses

n^2-3n+378

Back to the equation:

-(n^2-3n+378)


We get rid of parentheses

-n^2+3n-378=0

We add all the numbers together, and all the variables

-1n^2+3n-378=0

a = -1; b = 3; c = -378;
Δ = b2-4ac
Δ = 32-4·(-1)·(-378)
Δ = -1503
Delta is less than zero, so there is no solution for the equation