Subtract 21/81 from 42/7, Solve 6 0/7

Subtract 21/81 from 42/7

1^st number: 6 0/7, 2^nd number: 21/81

42/7 - 21/81 is 155/27.

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

Next, find the equivalent fraction of both fractional numbers with denominator 567
For the 1st fraction, since 7 × 81 = 567,
42/7 = 42 × 81/7 × 81 = 3402/567
Likewise, for the 2nd fraction, since 81 × 7 = 567,
21/81 = 21 × 7/81 × 7 = 147/567
Subtract the two like fractions:
3402/567 - 147/567 = 3402 - 147/567 = 3255/567
After reducing the fraction, the answer is 155/27
In mixed form: 520/27

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