Subtract 7/21 from 7/54
7/54 - 7/21 is -11/54.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 54 and 21 is 378
Next, find the equivalent fraction of both fractional numbers with denominator 378 - For the 1st fraction, since 54 × 7 = 378,
7/54 = 7 × 7/54 × 7 = 49/378 - Likewise, for the 2nd fraction, since 21 × 18 = 378,
7/21 = 7 × 18/21 × 18 = 126/378 - Subtract the two like fractions:
49/378 - 126/378 = 49 - 126/378 = -77/378 - After reducing the fraction, the answer is -11/54
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/54-7/21 7/54-14/21 7/54-7/42 21/54-7/21 7/54-7/63 35/54-7/21 7/54-35/21 49/54-7/21 7/54-49/21