Subtract 30/7 from 6/81, Solve 6/81

Subtract 30/7 from 6/81

1^st number: 6/81, 2^nd number: 4 2/7

6/81 - 30/7 is -796/189.

Find the least common denominator or LCM of the two denominators:
LCM of 81 and 7 is 567

Next, find the equivalent fraction of both fractional numbers with denominator 567
For the 1st fraction, since 81 × 7 = 567,
6/81 = 6 × 7/81 × 7 = 42/567
Likewise, for the 2nd fraction, since 7 × 81 = 567,
30/7 = 30 × 81/7 × 81 = 2430/567
Subtract the two like fractions:
42/567 - 2430/567 = 42 - 2430/567 = -2388/567
After reducing the fraction, the answer is -796/189

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