Question

`(2-n)!+(n-2)! =` ?

`(2-n)!+(n-2)!`

Answer 1

`2`

Explanation:

Note that factorial is undefined for negative integers, so the expression `(2-n)!+(n-2)!` is only defined for `n=2`, in which case:

`(2-n)!+(n-2)! = 0!+0! = 1+1 = 2`