Subtract 5/7 from 7/21
7/21 - 5/7 is -8/21.
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,
7/21 = 7 × 1/21 × 1 = 7/21 - Likewise, for the 2nd fraction, since 7 × 3 = 21,
5/7 = 5 × 3/7 × 3 = 15/21 - Subtract the two like fractions:
7/21 - 15/21 = 7 - 15/21 = -8/21
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