You need to know the least common denominator (LCD) of 9 and 72 if you want to add or subtract two fractions with 9 and 72 as denominators.
The least common denominator, also called lowest common denominator (LCD), of 9 and 72 is 72.
Here is a math problem example where you need to know the LCD of 9 and 72 to solve:
3/9 + 2/72 = ?
Step 1) Take the LCD and divide each denominator by it as follows:
72/9 = 8
72/72 = 1
Step 2) Multiply each nominator with the respective answers from Step 1:
3 x 8 = 24
2 x 1 = 2
Step 3) Put it all together to solve the problem:
24/72 + 2/72 = 26/72
= 3/9 + 2/72 = 26/72
It's that easy! Once again, the lowest common denominator (LCD) of 9 and 72 is as follows:
72
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