Hi my question is find the value of the following.

Question

6! 8! over 9! 5!

If your answer is not an integer, write it as an exact fraction.

Thank you so much. I have no idea how to do it.

Answer 1

quick way:
on your calculator find a key usually labeled n!
(on mine to find 6!, I keystroke like this:
6
2ndF
n!
=

to get 720
so for (6!8!)/(9!5!) you should get 2/3 or .6666...

or

use the definitions:
also recall that the concept that 9! = 9x8!
since this suits our expression nicely we can say
(6!8!)/(9!5!)
= (6x5! 8!)/(9x8! 5!) , now cancel the 8! and the 5! )
= 6/9 = 2/3

Answer 2

Thank you very much Reiny