Subtract 20/21 from 10/20
10/20 - 20/21 is -19/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 21 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 20 × 21 = 420,
10/20 = 10 × 21/20 × 21 = 210/420 - Likewise, for the 2nd fraction, since 21 × 20 = 420,
20/21 = 20 × 20/21 × 20 = 400/420 - Subtract the two like fractions:
210/420 - 400/420 = 210 - 400/420 = -190/420 - After reducing the fraction, the answer is -19/42
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