You need to know the least common denominator (LCD) of 28 and 9 if you want to add or subtract two fractions with 28 and 9 as denominators.
The least common denominator, also called lowest common denominator (LCD), of 28 and 9 is 252.
Here is a math problem example where you need to know the LCD of 28 and 9 to solve:
3/28 + 2/9 = ?
Step 1) Take the LCD and divide each denominator by it as follows:
252/28 = 9
252/9 = 28
Step 2) Multiply each nominator with the respective answers from Step 1:
3 x 9 = 27
2 x 28 = 56
Step 3) Put it all together to solve the problem:
27/252 + 56/252 = 83/252
= 3/28 + 2/9 = 83/252
It's that easy! Once again, the lowest common denominator (LCD) of 28 and 9 is as follows:
252
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