Subtract 9/12 from 70/21, Solve 3 7/21

Subtract 9/12 from 70/21

1^st number: 3 7/21, 2^nd number: 9/12

70/21 - 9/12 is 31/12.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 12 is 84

Next, find the equivalent fraction of both fractional numbers with denominator 84
For the 1st fraction, since 21 × 4 = 84,
70/21 = 70 × 4/21 × 4 = 280/84
Likewise, for the 2nd fraction, since 12 × 7 = 84,
9/12 = 9 × 7/12 × 7 = 63/84
Subtract the two like fractions:
280/84 - 63/84 = 280 - 63/84 = 217/84
After reducing the fraction, the answer is 31/12
In mixed form: 27/12

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