Subtract 21/81 from 2/5
2/5 - 21/81 is 19/135.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 5 and 81 is 405
Next, find the equivalent fraction of both fractional numbers with denominator 405 - For the 1st fraction, since 5 × 81 = 405,
2/5 = 2 × 81/5 × 81 = 162/405 - Likewise, for the 2nd fraction, since 81 × 5 = 405,
21/81 = 21 × 5/81 × 5 = 105/405 - Subtract the two like fractions:
162/405 - 105/405 = 162 - 105/405 = 57/405 - After reducing the fraction, the answer is 19/135
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