Subtract 21/81 from 42/84
42/84 - 21/81 is 13/54.
Steps for subtracting fractions
- 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 - For the 1st fraction, since 84 × 27 = 2268,
42/84 = 42 × 27/84 × 27 = 1134/2268 - Likewise, for the 2nd fraction, since 81 × 28 = 2268,
21/81 = 21 × 28/81 × 28 = 588/2268 - Subtract the two like fractions:
1134/2268 - 588/2268 = 1134 - 588/2268 = 546/2268 - After reducing the fraction, the answer is 13/54
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