Subtract 63/7 from 81/21
1st number: 3 18/21, 2nd number: 9 0/7
81/21 - 63/7 is -36/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 7 is 21
Next, find the equivalent fraction of both fractional numbers with denominator 21 - For the 1st fraction, since 21 × 1 = 21,
81/21 = 81 × 1/21 × 1 = 81/21 - Likewise, for the 2nd fraction, since 7 × 3 = 21,
63/7 = 63 × 3/7 × 3 = 189/21 - Subtract the two like fractions:
81/21 - 189/21 = 81 - 189/21 = -108/21 - After reducing the fraction, the answer is -36/7
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