SOLUTION: My question is about adding factorials. This seems easy but not sure. Question is 9! + 4! I understand that the nine is 9 8 7 6 5 4 3 2 1 then the 4 is 4

Algebra ->  Permutations -> SOLUTION: My question is about adding factorials. This seems easy but not sure. Question is 9! + 4! I understand that the nine is 9 8 7 6 5 4 3 2 1 then the 4 is 4       Log On


   

Question 76400: My question is about adding factorials. This seems easy but not sure.
Question is 9! + 4!

I understand that the nine is 9 8 7 6 5 4 3 2 1 then the 4 is 4 3 2 1 do you just add the numbers?????? Or what?
Thanks,
Gary
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Since 9! is 9*8*7*6*5*4*3*2*1 and 4! is 4*3*2*1 we have a common factor of 4*3*2*1 . So we can factor this out
4%2A3%2A2%2A1%289%2A8%2A7%2A6%2A5%2B1%29
24%2815120%2B1%29 Compute the factorials
24%2815121%29 Add
24%2815121%29
362904
This is just one way of doing it. You can just simply evaluate 9! and 4! and add the 2 large numbers together, but I thought I'd show you another way.