Subtract 8/12 from 7/21
7/21 - 8/12 is -1/3.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 12 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 21 × 4 = 84,
7/21 = 7 × 4/21 × 4 = 28/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
8/12 = 8 × 7/12 × 7 = 56/84 - Subtract the two like fractions:
28/84 - 56/84 = 28 - 56/84 = -28/84 - After reducing the fraction, the answer is -1/3
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