9=n(n+3)/2

Solution for 9=n(n+3)/2 equation:

9=n(n+3)/2

We move all terms to the left:

9-(n(n+3)/2)=0

We multiply all the terms by the denominator


-(n(n+3)+9*2)=0


We calculate terms in parentheses: -(n(n+3)+9*2), so:

n(n+3)+9*2

We add all the numbers together, and all the variables

n(n+3)+18

We multiply parentheses

n^2+3n+18

Back to the equation:

-(n^2+3n+18)


We get rid of parentheses

-n^2-3n-18=0

We add all the numbers together, and all the variables

-1n^2-3n-18=0

a = -1; b = -3; c = -18;
Δ = b2-4ac
Δ = -32-4·(-1)·(-18)
Δ = -63
Delta is less than zero, so there is no solution for the equation