Question

If (n+1)! = 12 x (n-1)! then find the value of n ?​

Answer 1

Answer:

n=3

Step-by-step explanation:

(n+1)!=12(n−1)!

(n(n+1)−12)(n−1)!=0 [n!=n(n−1)!]

As (n−1)! cannot be zero

=>(n(n+1)−12)=0

n2+n−12=0

n2+4n−3n−12=0

(n+4)(n−3)=0

Either n=−4 or n=3

For n=−4,(n−1)! is not defined

=> Value of n is 3

Answer 2

Step-by-step explanation:

(n+1)!=12*(n-1)!

(n+1)!

--------- = 12

(n-1)!

=n*(n+1)=12

n²+n-22=0

n=3