Subtract 45/14 from 21/81, Solve 21/81

Subtract 45/14 from 21/81

1^st number: 21/81, 2^nd number: 3 3/14

21/81 - 45/14 is -1117/378.

Find the least common denominator or LCM of the two denominators:
LCM of 81 and 14 is 1134

Next, find the equivalent fraction of both fractional numbers with denominator 1134
For the 1st fraction, since 81 × 14 = 1134,
21/81 = 21 × 14/81 × 14 = 294/1134
Likewise, for the 2nd fraction, since 14 × 81 = 1134,
45/14 = 45 × 81/14 × 81 = 3645/1134
Subtract the two like fractions:
294/1134 - 3645/1134 = 294 - 3645/1134 = -3351/1134
After reducing the fraction, the answer is -1117/378

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