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