for this question we're going to find the lowest common multiple of 15 and 18. so the method that we're going to use here is that we're going to list out all of the multiples of 15 and 18. so 15 and 18 are not multiples of each other since as 18 is only 3 larger than 15. so what we're going to do is list out the multiples of each so at 15 and 18 and then we're going to see when the next lowest number that both of them multiply into is going to be so 15 times 1 is 15 then we have 30 45 60 75 90 and 105. so we have a few listed out for 15 and we'll go with 18 now so we have 18 36. 54 72 now we have 90. so that means that our lowest common multiple of these two numbers is 90.