how do i find a least common multiple?

Question

anonymous · Answer

lets  say LCM of 9 and 5 
9 and 5 are the only factor for them hence 9x5 is LCM 

2  |12 , 36 
2    |6 , 18
3   |3 , 9 
     |1, 3 
3x3x2x2 is LCM

anonymous · Answer

List the multiples of each number, then look for the smallest number that appears in each list.

For example, the least common multiple for 5, 6, and 15. List the multiples of each number.

Multiples of 5 are 5, 10, 15, 20, 25, 30, 35, 40,...

Multiples of 6 are 6, 12, 18, 24, 30, 36, 42, 48,...

Multiples of 15 are 15, 30, 45, 60, 75, 90,....

You can see that 30 is the smallest number that appears in each list.
Therefore, the least common multiple of 5, 6 and 15 is 30.

anonymous · Answer

ooooooh ok so its um like the factor tree thing ?? riight?