Subtract 1/18 from 1/21
1/21 - 1/18 is -1/126.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 21 × 6 = 126,
1/21 = 1 × 6/21 × 6 = 6/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
1/18 = 1 × 7/18 × 7 = 7/126 - Subtract the two like fractions:
6/126 - 7/126 = 6 - 7/126 = -1/126
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