Subtract 20/24 from 3/21
3/21 - 20/24 is -29/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 24 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 21 × 8 = 168,
3/21 = 3 × 8/21 × 8 = 24/168 - Likewise, for the 2nd fraction, since 24 × 7 = 168,
20/24 = 20 × 7/24 × 7 = 140/168 - Subtract the two like fractions:
24/168 - 140/168 = 24 - 140/168 = -116/168 - After reducing the fraction, the answer is -29/42
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