Subtract 20/21 from 6/8
6/8 - 20/21 is -17/84.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 8 and 21 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 8 × 21 = 168,
6/8 = 6 × 21/8 × 21 = 126/168 - Likewise, for the 2nd fraction, since 21 × 8 = 168,
20/21 = 20 × 8/21 × 8 = 160/168 - Subtract the two like fractions:
126/168 - 160/168 = 126 - 160/168 = -34/168 - After reducing the fraction, the answer is -17/84
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