Subtract 20/12 from 20/21
1st number: 20/21, 2nd number: 1 8/12
20/21 - 20/12 is -5/7.
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,
20/21 = 20 × 4/21 × 4 = 80/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
20/12 = 20 × 7/12 × 7 = 140/84 - Subtract the two like fractions:
80/84 - 140/84 = 80 - 140/84 = -60/84 - After reducing the fraction, the answer is -5/7
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