Subtract 8/36 from 81/21, Solve 3 18/21

Subtract 8/36 from 81/21

1^st number: 3 18/21, 2^nd number: 8/36

81/21 - 8/36 is 229/63.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 36 is 252

Next, find the equivalent fraction of both fractional numbers with denominator 252
For the 1st fraction, since 21 × 12 = 252,
81/21 = 81 × 12/21 × 12 = 972/252
Likewise, for the 2nd fraction, since 36 × 7 = 252,
8/36 = 8 × 7/36 × 7 = 56/252
Subtract the two like fractions:
972/252 - 56/252 = 972 - 56/252 = 916/252
After reducing the fraction, the answer is 229/63
In mixed form: 340/63

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