Subtract 5/20 from 15/81
15/81 - 5/20 is -7/108.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 20 is 1620
Next, find the equivalent fraction of both fractional numbers with denominator 1620 - For the 1st fraction, since 81 × 20 = 1620,
15/81 = 15 × 20/81 × 20 = 300/1620 - Likewise, for the 2nd fraction, since 20 × 81 = 1620,
5/20 = 5 × 81/20 × 81 = 405/1620 - Subtract the two like fractions:
300/1620 - 405/1620 = 300 - 405/1620 = -105/1620 - After reducing the fraction, the answer is -7/108
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