Respuesta :

When you end up with prime numbers for example
If you factored out 12 you could say 3x4. Now 3 is a prime number so it cant be broken down any more. You can break down 4 into 2x2. 2 is a prime number so cant be broken down any further. When 12 is factored out it is 2x2x3
When you come to a number that you can't divide any more