What is the lcd of 4,6,18 Answer: 36 Step-by-step explanation: To know the LCD, just list the multiples of the numbers. So start on their first ten multiple. 4-4,8,12,16,20,24,28,32,36,40 6-6,12,18,24,30,36,42,48,54,60 18-18,36,54,72,90,108,126,144,162,180 Then list their common multiple. Common multiple-36 So, on their first ten multiple, their only common multiple is 36. So, thats the lowest common multiple/denominator.