Subtract 21/54 from 5/21
5/21 - 21/54 is -19/126.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 54 is 378
Next, find the equivalent fraction of both fractional numbers with denominator 378 - For the 1st fraction, since 21 × 18 = 378,
5/21 = 5 × 18/21 × 18 = 90/378 - Likewise, for the 2nd fraction, since 54 × 7 = 378,
21/54 = 21 × 7/54 × 7 = 147/378 - Subtract the two like fractions:
90/378 - 147/378 = 90 - 147/378 = -57/378 - After reducing the fraction, the answer is -19/126
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