Subtract 28/12 from 20/21
1st number: 20/21, 2nd number: 2 4/12
20/21 - 28/12 is -29/21.
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,
28/12 = 28 × 7/12 × 7 = 196/84 - Subtract the two like fractions:
80/84 - 196/84 = 80 - 196/84 = -116/84 - After reducing the fraction, the answer is -29/21
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