Subtract 20/72 from 1/81
1/81 - 20/72 is -43/162.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 72 is 648
Next, find the equivalent fraction of both fractional numbers with denominator 648 - For the 1st fraction, since 81 × 8 = 648,
1/81 = 1 × 8/81 × 8 = 8/648 - Likewise, for the 2nd fraction, since 72 × 9 = 648,
20/72 = 20 × 9/72 × 9 = 180/648 - Subtract the two like fractions:
8/648 - 180/648 = 8 - 180/648 = -172/648 - After reducing the fraction, the answer is -43/162
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