Subtract 42/81 from 20/45
20/45 - 42/81 is -2/27.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 81 is 405
Next, find the equivalent fraction of both fractional numbers with denominator 405 - For the 1st fraction, since 45 × 9 = 405,
20/45 = 20 × 9/45 × 9 = 180/405 - Likewise, for the 2nd fraction, since 81 × 5 = 405,
42/81 = 42 × 5/81 × 5 = 210/405 - Subtract the two like fractions:
180/405 - 210/405 = 180 - 210/405 = -30/405 - After reducing the fraction, the answer is -2/27
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