Subtract 20/21 from 6/12
6/12 - 20/21 is -19/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 12 × 7 = 84,
6/12 = 6 × 7/12 × 7 = 42/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
20/21 = 20 × 4/21 × 4 = 80/84 - Subtract the two like fractions:
42/84 - 80/84 = 42 - 80/84 = -38/84 - After reducing the fraction, the answer is -19/42
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