Subtract 5/21 from 18/81
18/81 - 5/21 is -1/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 21 is 567
Next, find the equivalent fraction of both fractional numbers with denominator 567 - For the 1st fraction, since 81 × 7 = 567,
18/81 = 18 × 7/81 × 7 = 126/567 - Likewise, for the 2nd fraction, since 21 × 27 = 567,
5/21 = 5 × 27/21 × 27 = 135/567 - Subtract the two like fractions:
126/567 - 135/567 = 126 - 135/567 = -9/567 - After reducing the fraction, the answer is -1/63
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