Question: what is the lcm of 10 and 12 using prime factorization?
Answer: The LCM of two numbers is the result of multiplying the prime factors of the first number, and the prime factors of the second number *without* those factors in the first number. So the LCM of 10 and 12 is 2x5(first number)x3x3(second number with the common number from the first number removed), or *60*.