You need to know the least common denominator (LCD) of 85 and 72 if you want to add or subtract two fractions with 85 and 72 as denominators.
The least common denominator, also called lowest common denominator (LCD), of 85 and 72 is 6120.
Here is a math problem example where you need to know the LCD of 85 and 72 to solve:
3/85 + 2/72 = ?
Step 1) Take the LCD and divide each denominator by it as follows:
6120/85 = 72
6120/72 = 85
Step 2) Multiply each nominator with the respective answers from Step 1:
3 x 72 = 216
2 x 85 = 170
Step 3) Put it all together to solve the problem:
216/6120 + 170/6120 = 386/6120
= 3/85 + 2/72 = 386/6120
It's that easy! Once again, the lowest common denominator (LCD) of 85 and 72 is as follows:
6120
Find Least Common Denominators
Enter another two numbers below to find the Least Common Denominator.