Subtract 81/21 from 72/12
1st number: 6 0/12, 2nd number: 3 18/21
72/12 - 81/21 is 15/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 12 × 7 = 84,
72/12 = 72 × 7/12 × 7 = 504/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
81/21 = 81 × 4/21 × 4 = 324/84 - Subtract the two like fractions:
504/84 - 324/84 = 504 - 324/84 = 180/84 - After reducing the fraction, the answer is 15/7
- In mixed form: 21/7
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