Question

Evaluate

1. (n-2)! x (n-1)
2. n x (n-1)!

Answer 1

you know factorial of a number?

Answer 2

@JaneReducto reply :)

Answer 3

let's see, 3! = factorial of 3 = 1*2*3 { multiplication of numbers from 1 to given number, here 3}

that way 5! = 1*2*3*4*5

now n! = 1*2*3*........(n-2)*(n-1)*n rigth?

Answer 4

we generally have these below right
4! = 1*2*3*4
5! = 1*2*3*4*5
5! = (1*2*3*4)*5 = 4!*5

Answer 5

for your second problem, if you take n = 5, thne n-1 will be 4
so 4!*5 is actually 5 right?
so (n-1)!*n will be n!

Answer 6

Please note that, using the definition of factorial, we have:
\[(n-2)!*(n-1)=(n-1)!\]
since (n-1) is next of (n-2),
and similarly,we can write:
\[(n-1)!*n=n!\]
since n is the next of (n-1)