CPM Homework Help : A2C Problem 10-78

Write an equivalent expression for each of the following situations that does not include the factorial (!) symbol.

The first five factors of $\left(n − 3\right)!$
Answer (a):
$\left(n − 3\right) \left(n − 4\right) \left(n − 5\right) \left(n − 6\right) \left(n − 7\right)$

$\frac { n ! } { ( n - 3 ) ! }$
Hint (c):
$\frac{n!}{(n-3)!}=\frac{n(n-1)(n-2)(n-3)(n-4)...}{(n-3)(n-4)...}$
Answer (c):
$n\left(n − 1\right) \left(n − 2\right)$