Subtract 20/5 from 21/81
1st number: 21/81, 2nd number: 4 0/5
21/81 - 20/5 is -101/27.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 5 is 405
Next, find the equivalent fraction of both fractional numbers with denominator 405 - For the 1st fraction, since 81 × 5 = 405,
21/81 = 21 × 5/81 × 5 = 105/405 - Likewise, for the 2nd fraction, since 5 × 81 = 405,
20/5 = 20 × 81/5 × 81 = 1620/405 - Subtract the two like fractions:
105/405 - 1620/405 = 105 - 1620/405 = -1515/405 - After reducing the fraction, the answer is -101/27
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