Subtract 20/54 from 20/42
20/42 - 20/54 is 20/189.
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,
20/54 = 20 × 7/54 × 7 = 140/378 - Subtract the two like fractions:
180/378 - 140/378 = 180 - 140/378 = 40/378 - After reducing the fraction, the answer is 20/189
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/42-20/54 20/42-40/54 20/84-20/54 60/42-20/54 20/42-60/54