Subtract 21/84 from 8/81
8/81 - 21/84 is -49/324.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 84 is 2268
Next, find the equivalent fraction of both fractional numbers with denominator 2268 - For the 1st fraction, since 81 × 28 = 2268,
8/81 = 8 × 28/81 × 28 = 224/2268 - Likewise, for the 2nd fraction, since 84 × 27 = 2268,
21/84 = 21 × 27/84 × 27 = 567/2268 - Subtract the two like fractions:
224/2268 - 567/2268 = 224 - 567/2268 = -343/2268 - After reducing the fraction, the answer is -49/324
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