Subtract 21/30 from 72/81
72/81 - 21/30 is 17/90.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 30 is 810
Next, find the equivalent fraction of both fractional numbers with denominator 810 - For the 1st fraction, since 81 × 10 = 810,
72/81 = 72 × 10/81 × 10 = 720/810 - Likewise, for the 2nd fraction, since 30 × 27 = 810,
21/30 = 21 × 27/30 × 27 = 567/810 - Subtract the two like fractions:
720/810 - 567/810 = 720 - 567/810 = 153/810 - After reducing the fraction, the answer is 17/90
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