Subtract 9/42 from 20/21
20/21 - 9/42 is 31/42.
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,
20/21 = 20 × 2/21 × 2 = 40/42 - Likewise, for the 2nd fraction, since 42 × 1 = 42,
9/42 = 9 × 1/42 × 1 = 9/42 - Subtract the two like fractions:
40/42 - 9/42 = 40 - 9/42 = 31/42
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