Subtract 81/21 from 6/27, Solve 6/27

Subtract 81/21 from 6/27

1^st number: 6/27, 2^nd number: 3 18/21

6/27 - 81/21 is -229/63.

Find the least common denominator or LCM of the two denominators:
LCM of 27 and 21 is 189

Next, find the equivalent fraction of both fractional numbers with denominator 189
For the 1st fraction, since 27 × 7 = 189,
6/27 = 6 × 7/27 × 7 = 42/189
Likewise, for the 2nd fraction, since 21 × 9 = 189,
81/21 = 81 × 9/21 × 9 = 729/189
Subtract the two like fractions:
42/189 - 729/189 = 42 - 729/189 = -687/189
After reducing the fraction, the answer is -229/63

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