Subtract 45/81 from 21/49
21/49 - 45/81 is -8/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 49 and 81 is 3969
Next, find the equivalent fraction of both fractional numbers with denominator 3969 - For the 1st fraction, since 49 × 81 = 3969,
21/49 = 21 × 81/49 × 81 = 1701/3969 - Likewise, for the 2nd fraction, since 81 × 49 = 3969,
45/81 = 45 × 49/81 × 49 = 2205/3969 - Subtract the two like fractions:
1701/3969 - 2205/3969 = 1701 - 2205/3969 = -504/3969 - After reducing the fraction, the answer is -8/63
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