Subtract 20/90 from 10/81
10/81 - 20/90 is -8/81.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 90 is 810
Next, find the equivalent fraction of both fractional numbers with denominator 810 - For the 1st fraction, since 81 × 10 = 810,
10/81 = 10 × 10/81 × 10 = 100/810 - Likewise, for the 2nd fraction, since 90 × 9 = 810,
20/90 = 20 × 9/90 × 9 = 180/810 - Subtract the two like fractions:
100/810 - 180/810 = 100 - 180/810 = -80/810 - After reducing the fraction, the answer is -8/81
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