Thursday

November 20, 2014

November 20, 2014

Posted by **emily** on Wednesday, September 30, 2009 at 7:55pm.

- 8th grade math -
**jim**, Wednesday, September 30, 2009 at 8:06pmWrite down the prime factors of each.

Look at all the factors, of both numbers, together.

The LCM will be the smallest set of this list from which you can make either of the two original numbers.

Example:

30 = 2 * 3 * 5

24 = 2 * 2 * 2 * 3

So we have 2, 2, 2, 2, 3, 3, 5 to choose from, and we need to choose a set from that that will make either of our numbers. That set is: 2 * 2 * 2 * 3 * 5, which is 120.

Now, for the GCF, we need to choose as many of the factors as both number have in common:

30 = 2 * 3 * 5

24 = 2 * 2 * 2 * 3

2 and 3 are in both (only one two, since 30 has only one two), so 2 * 3 = 6 is the GCF.

**Answer this Question**

**Related Questions**

math - What methods can you use to find prime numbers? How are prime numbers ...

math - How do the ideas of divisibility and multiples relate to the study of ...

Math - What is a unit rate? what is the prime factorazation for 945? idk how to ...

Math - When dealing with GCF, LCM and divisiability do prime factorization help ...

math,algebra,bobpursley - Let me know if this is correct now: (1)Finding the lcm...

Math - I am 55, my motherlaw is 70, my friend is 40. How do I figure out the LCM...

8th grade math - If two numbers are relatively prime, what is their LCM? Explain...

math , algebra - Let me know if this is correct : (1)Finding the lcm using which...

MAT126: Survey of Mathematical Methods - All numbers in our real number system ...

math - Find the GCF of the numbers using an appropriate method. 240, 10,000, and...