Subtract 72/21 from 15/42
1st number: 15/42, 2nd number: 3 9/21
15/42 - 72/21 is -43/14.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 21 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 42 × 1 = 42,
15/42 = 15 × 1/42 × 1 = 15/42 - Likewise, for the 2nd fraction, since 21 × 2 = 42,
72/21 = 72 × 2/21 × 2 = 144/42 - Subtract the two like fractions:
15/42 - 144/42 = 15 - 144/42 = -129/42 - After reducing the fraction, the answer is -43/14
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