Subtract 28/54 from 30/21
1st number: 1 9/21, 2nd number: 28/54
30/21 - 28/54 is 172/189.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 54 is 378
Next, find the equivalent fraction of both fractional numbers with denominator 378 - For the 1st fraction, since 21 × 18 = 378,
30/21 = 30 × 18/21 × 18 = 540/378 - Likewise, for the 2nd fraction, since 54 × 7 = 378,
28/54 = 28 × 7/54 × 7 = 196/378 - Subtract the two like fractions:
540/378 - 196/378 = 540 - 196/378 = 344/378 - After reducing the fraction, the answer is 172/189
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/21-28/54 30/21-56/54 30/42-28/54 90/21-28/54 30/21-84/54 30/63-28/54