Subtract 12/8 from 20/21
1st number: 20/21, 2nd number: 1 4/8
20/21 - 12/8 is -23/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 8 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 21 × 8 = 168,
20/21 = 20 × 8/21 × 8 = 160/168 - Likewise, for the 2nd fraction, since 8 × 21 = 168,
12/8 = 12 × 21/8 × 21 = 252/168 - Subtract the two like fractions:
160/168 - 252/168 = 160 - 252/168 = -92/168 - After reducing the fraction, the answer is -23/42
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