Subtract 21/42 from 7/21
7/21 - 21/42 is -1/6.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 42 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 21 × 2 = 42,
7/21 = 7 × 2/21 × 2 = 14/42 - Likewise, for the 2nd fraction, since 42 × 1 = 42,
21/42 = 21 × 1/42 × 1 = 21/42 - Subtract the two like fractions:
14/42 - 21/42 = 14 - 21/42 = -7/42 - After reducing the fraction, the answer is -1/6
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