Subtract 72/63 from 21/28
1st number: 21/28, 2nd number: 1 9/63
21/28 - 72/63 is -11/28.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 63 is 252
Next, find the equivalent fraction of both fractional numbers with denominator 252 - For the 1st fraction, since 28 × 9 = 252,
21/28 = 21 × 9/28 × 9 = 189/252 - Likewise, for the 2nd fraction, since 63 × 4 = 252,
72/63 = 72 × 4/63 × 4 = 288/252 - Subtract the two like fractions:
189/252 - 288/252 = 189 - 288/252 = -99/252 - After reducing the fraction, the answer is -11/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/28-72/63 21/56-72/63 63/28-72/63 21/84-72/63