Subtract 3/42 from 21/54
21/54 - 3/42 is 20/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 54 and 42 is 378
Next, find the equivalent fraction of both fractional numbers with denominator 378 - For the 1st fraction, since 54 × 7 = 378,
21/54 = 21 × 7/54 × 7 = 147/378 - Likewise, for the 2nd fraction, since 42 × 9 = 378,
3/42 = 3 × 9/42 × 9 = 27/378 - Subtract the two like fractions:
147/378 - 27/378 = 147 - 27/378 = 120/378 - After reducing the fraction, the answer is 20/63
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