Subtract 3/12 from 3/21
3/21 - 3/12 is -3/28.
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,
3/21 = 3 × 4/21 × 4 = 12/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
3/12 = 3 × 7/12 × 7 = 21/84 - Subtract the two like fractions:
12/84 - 21/84 = 12 - 21/84 = -9/84 - After reducing the fraction, the answer is -3/28
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