Subtract 18/8 from 81/21
1st number: 3 18/21, 2nd number: 2 2/8
81/21 - 18/8 is 45/28.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 8 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 21 × 8 = 168,
81/21 = 81 × 8/21 × 8 = 648/168 - Likewise, for the 2nd fraction, since 8 × 21 = 168,
18/8 = 18 × 21/8 × 21 = 378/168 - Subtract the two like fractions:
648/168 - 378/168 = 648 - 378/168 = 270/168 - After reducing the fraction, the answer is 45/28
- In mixed form: 117/28
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