Subtract 4/7 from 21/54
21/54 - 4/7 is -23/126.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 54 and 7 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 7 × 54 = 378,
4/7 = 4 × 54/7 × 54 = 216/378 - Subtract the two like fractions:
147/378 - 216/378 = 147 - 216/378 = -69/378 - After reducing the fraction, the answer is -23/126
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/54-4/7 21/54-8/7 21/54-4/14 63/54-4/7 21/54-12/7 21/54-4/21 21/54-20/7 21/54-4/35 21/54-28/7 21/54-4/49