Subtract 6/7 from 3/21
3/21 - 6/7 is -5/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 7 is 21
Next, find the equivalent fraction of both fractional numbers with denominator 21 - For the 1st fraction, since 21 × 1 = 21,
3/21 = 3 × 1/21 × 1 = 3/21 - Likewise, for the 2nd fraction, since 7 × 3 = 21,
6/7 = 6 × 3/7 × 3 = 18/21 - Subtract the two like fractions:
3/21 - 18/21 = 3 - 18/21 = -15/21 - After reducing the fraction, the answer is -5/7
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