Subtract 21/7 from 81/18
1st number: 4 9/18, 2nd number: 3 0/7
81/18 - 21/7 is 3/2.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 7 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 18 × 7 = 126,
81/18 = 81 × 7/18 × 7 = 567/126 - Likewise, for the 2nd fraction, since 7 × 18 = 126,
21/7 = 21 × 18/7 × 18 = 378/126 - Subtract the two like fractions:
567/126 - 378/126 = 567 - 378/126 = 189/126 - After reducing the fraction, the answer is 3/2
- In mixed form: 11/2
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