Take any number (except for 1). Square that number and then subtract one. Divide by one less than your original number. Now subtract your original number. You reached 1 for an answer, didn’t you? How does this number game work?
(n^2-1)/(n-1) - n = ?
(n-1)(n+1)/(n-1) -n =?
n+1-n = n
duh