Recall the permutation formula: nPr = n!/(n-r)!
In this question, n=9 and r= 4
Let's plug in those values into the formula
9!/(9-4)! = 9!/5! = 3024
The final answer is 3024!
[tex] _9P_4=\frac{9!}{5!}=\frac{9*8*7*6*(5*4*3*2*1)}{(5*4*3*2*1}=9*8*7*6*5=3024 [/tex]
