Answers

Subtract 21/81 from 75/84

75/84 - 21/81 is 479/756.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 84 and 81 is 2268
   
   Next, find the equivalent fraction of both fractional numbers with denominator 2268
2. For the 1st fraction, since 84 × 27 = 2268,
   75/84 = 75 × 27/84 × 27 = 2025/2268
3. Likewise, for the 2nd fraction, since 81 × 28 = 2268,
   21/81 = 21 × 28/81 × 28 = 588/2268
4. Subtract the two like fractions:
   2025/2268 - 588/2268 = 2025 - 588/2268 = 1437/2268
5. After reducing the fraction, the answer is 479/756

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