You need to know the least common denominator (LCD) of 7 and 87 if you want to add or subtract two fractions with 7 and 87 as denominators.
The least common denominator, also called lowest common denominator (LCD), of 7 and 87 is 609.
Here is a math problem example where you need to know the LCD of 7 and 87 to solve:
3/7 + 2/87 = ?
Step 1) Take the LCD and divide each denominator by it as follows:
609/7 = 87
609/87 = 7
Step 2) Multiply each nominator with the respective answers from Step 1:
3 x 87 = 261
2 x 7 = 14
Step 3) Put it all together to solve the problem:
261/609 + 14/609 = 275/609
= 3/7 + 2/87 = 275/609
It's that easy! Once again, the lowest common denominator (LCD) of 7 and 87 is as follows:
609
Find Least Common Denominators
Enter another two numbers below to find the Least Common Denominator.