Question

n(n-1)/2=6 find value of n?

Answer 1

Answer:

-3 or 4

Explanation:

n(n-1)/2=6

n(n-1)=6*2

n^2-n =12

n^2-n-12=0

now, as we know factors of 12 is 3 and 4 and difference between two factors is 1.

hence

n^2-4n+3n-12=0

n(n-4)+3(n-4)=0

(n-4)(n+3)=0

So, n= -3 or 4