Subtract 54/7 from 28/21
1st number: 1 7/21, 2nd number: 7 5/7
28/21 - 54/7 is -134/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 7 is 21
Next, find the equivalent fraction of both fractional numbers with denominator 21 - For the 1st fraction, since 21 × 1 = 21,
28/21 = 28 × 1/21 × 1 = 28/21 - Likewise, for the 2nd fraction, since 7 × 3 = 21,
54/7 = 54 × 3/7 × 3 = 162/21 - Subtract the two like fractions:
28/21 - 162/21 = 28 - 162/21 = -134/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/21-54/7 28/42-54/7 28/21-54/14 84/21-54/7 28/63-54/7 28/21-54/21 28/21-54/35 28/21-54/49