Subtract 21/54 from 42/63
42/63 - 21/54 is 5/18.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 63 and 54 is 378
Next, find the equivalent fraction of both fractional numbers with denominator 378 - For the 1st fraction, since 63 × 6 = 378,
42/63 = 42 × 6/63 × 6 = 252/378 - Likewise, for the 2nd fraction, since 54 × 7 = 378,
21/54 = 21 × 7/54 × 7 = 147/378 - Subtract the two like fractions:
252/378 - 147/378 = 252 - 147/378 = 105/378 - After reducing the fraction, the answer is 5/18
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/63-21/54 42/63-42/54 42/63-63/54