Subtract 3/21 from 81/12, Solve 6 9/12

Subtract 3/21 from 81/12

1^st number: 6 9/12, 2^nd number: 3/21

81/12 - 3/21 is 185/28.

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,
81/12 = 81 × 7/12 × 7 = 567/84
Likewise, for the 2nd fraction, since 21 × 4 = 84,
3/21 = 3 × 4/21 × 4 = 12/84
Subtract the two like fractions:
567/84 - 12/84 = 567 - 12/84 = 555/84
After reducing the fraction, the answer is 185/28
In mixed form: 617/28

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