Subtract 20/72 from 4/21
4/21 - 20/72 is -11/126.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 72 is 504
Next, find the equivalent fraction of both fractional numbers with denominator 504 - For the 1st fraction, since 21 × 24 = 504,
4/21 = 4 × 24/21 × 24 = 96/504 - Likewise, for the 2nd fraction, since 72 × 7 = 504,
20/72 = 20 × 7/72 × 7 = 140/504 - Subtract the two like fractions:
96/504 - 140/504 = 96 - 140/504 = -44/504 - After reducing the fraction, the answer is -11/126
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