Subtract 56/90 from 81/21, Solve 3 18/21

Subtract 56/90 from 81/21

1^st number: 3 18/21, 2^nd number: 56/90

81/21 - 56/90 is 1019/315.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 90 is 630

Next, find the equivalent fraction of both fractional numbers with denominator 630
For the 1st fraction, since 21 × 30 = 630,
81/21 = 81 × 30/21 × 30 = 2430/630
Likewise, for the 2nd fraction, since 90 × 7 = 630,
56/90 = 56 × 7/90 × 7 = 392/630
Subtract the two like fractions:
2430/630 - 392/630 = 2430 - 392/630 = 2038/630
After reducing the fraction, the answer is 1019/315
In mixed form: 374/315

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