You need to know the least common denominator (LCD) of 81 and 4 if you want to add or subtract two fractions with 81 and 4 as denominators.
The least common denominator, also called lowest common denominator (LCD), of 81 and 4 is 324.
Here is a math problem example where you need to know the LCD of 81 and 4 to solve:
3/81 + 2/4 = ?
Step 1) Take the LCD and divide each denominator by it as follows:
324/81 = 4
324/4 = 81
Step 2) Multiply each nominator with the respective answers from Step 1:
3 x 4 = 12
2 x 81 = 162
Step 3) Put it all together to solve the problem:
12/324 + 162/324 = 174/324
= 3/81 + 2/4 = 174/324
It's that easy! Once again, the lowest common denominator (LCD) of 81 and 4 is as follows:
324
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