Explanation
Factorial, in mathematics, the product of all positive integers less than or equal to a given positive integer and denoted by that integer and an exclamation point.
[tex]a![/tex]so, to evaluate the expression we need to apply the definition
hence
[tex]\begin{gathered} 12\text{ ! = 12}\cdot11\cdot10\cdot9\cdot8\cdot7\cdot6\cdot5\cdot4\cdot3\cdot2\cdot1 \\ 12\text{ ! =}479001600 \end{gathered}[/tex]I hope this helps you
