Subtract 90/81 from 21/7
1st number: 3 0/7, 2nd number: 1 9/81
21/7 - 90/81 is 17/9.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 7 and 81 is 567
Next, find the equivalent fraction of both fractional numbers with denominator 567 - For the 1st fraction, since 7 × 81 = 567,
21/7 = 21 × 81/7 × 81 = 1701/567 - Likewise, for the 2nd fraction, since 81 × 7 = 567,
90/81 = 90 × 7/81 × 7 = 630/567 - Subtract the two like fractions:
1701/567 - 630/567 = 1701 - 630/567 = 1071/567 - After reducing the fraction, the answer is 17/9
- In mixed form: 18/9
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