Remember that any natural number can be written as a product of prime numbers. Prime numbers are those numbers that are only divisible by one and themselves.
In the case of 72:
[tex]\begin{gathered} 72=9\cdot8 \\ \Rightarrow72=(3\cdot3)\cdot(2\cdot2\cdot2) \\ \Rightarrow72=2^3\cdot3^2 \end{gathered}[/tex]Therefore, the answer is the third option 72=2^3*3^2
