Question

8!=5!_

Answer 1

how does 8 factorial= 5 factorial? no such thing? whats the underscore?

Answer 2

8!=8*7!=8*7*6!=8*7*6*5!

Answer 3

I guess this question is not just that, when I studied permutation, I confused when my prof stated \[8P5= \frac{8!}{5!}=\frac{8!}{3!}= 8*7*6\]I made the same question: how 5! =3! hihihi... .