What does it mean to 'use prime factorization to find the LCM' ( 10 points best answer)

I'm really stuck on my homework, one of them is 9,21 could you do that for an example?

Thank you SO much!!

1.) Prime factorize both numbers: 9=3^2; 21= 3*7.
2.) How do we make these numbers equal? Multiply 9 by 7 and 21 by 3. So, 3^2*7=3*7*3=63.
So, LCM(9,21)=63.

The link below explains this process in more depth.

The first step in using primes for finding LCM is to find the prime factors of the given numbers.
The LCM of the given numbers is the product of all the prime factors to their greatest power.
Prime factors of 9 are 3^2
Prime factors of 21 are 3*7. (Ignore the 3 because 3^2 is the same prime to a greater power.)
The LCM of 9 and 21 is 3^2*7=3*3*7=63

It means to break up each number into its prime factor and then multiply the factors to get the lcm. Any common factors only get multiplied once.

9 = 3 * 3
21 = 3 * 7

9 and 21 have a 3 in common but 9 has an extra 3 and 21 has a 7. The lcm will be 3 * 3 * 7 = 63

every number can be expressed as a product of primes or exponeniated primes.
9 = 3 * 3 = 3^2
21 = 3 * 7
So, the lcm has to be 3^2 * 7 = 63

I don't know