Well, first of all, LCM means Lowest Common Multiple. So you have to write out the factors of each of the numbers. So that will be; 2= 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 5=5, 10, 15, 20 So now, you have to pick out the numbers that are common to both numbers. So; 10, 20 10 and 20 are the only common numbers. So you have to look for the lowest common number. And that is 10. So the LCM is 10.. Hope i helped. Have a nice day.
