Subtract 3/81 from 21/72
21/72 - 3/81 is 55/216.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 81 is 648
Next, find the equivalent fraction of both fractional numbers with denominator 648 - For the 1st fraction, since 72 × 9 = 648,
21/72 = 21 × 9/72 × 9 = 189/648 - Likewise, for the 2nd fraction, since 81 × 8 = 648,
3/81 = 3 × 8/81 × 8 = 24/648 - Subtract the two like fractions:
189/648 - 24/648 = 189 - 24/648 = 165/648 - After reducing the fraction, the answer is 55/216
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