Subtract 28/54 from 20/42
20/42 - 28/54 is -8/189.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 54 is 378
Next, find the equivalent fraction of both fractional numbers with denominator 378 - For the 1st fraction, since 42 × 9 = 378,
20/42 = 20 × 9/42 × 9 = 180/378 - Likewise, for the 2nd fraction, since 54 × 7 = 378,
28/54 = 28 × 7/54 × 7 = 196/378 - Subtract the two like fractions:
180/378 - 196/378 = 180 - 196/378 = -16/378 - After reducing the fraction, the answer is -8/189
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