Subtract 3/20 from 1/21
1/21 - 3/20 is -43/420.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 21 × 20 = 420,
1/21 = 1 × 20/21 × 20 = 20/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
3/20 = 3 × 21/20 × 21 = 63/420 - Subtract the two like fractions:
20/420 - 63/420 = 20 - 63/420 = -43/420
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