Subtract 30/54 from 10/21
10/21 - 30/54 is -5/63.
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,
10/21 = 10 × 18/21 × 18 = 180/378 - Likewise, for the 2nd fraction, since 54 × 7 = 378,
30/54 = 30 × 7/54 × 7 = 210/378 - Subtract the two like fractions:
180/378 - 210/378 = 180 - 210/378 = -30/378 - After reducing the fraction, the answer is -5/63
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