Subtract 21/9 from 30/8
1st number: 3 6/8, 2nd number: 2 3/9
30/8 - 21/9 is 17/12.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 8 and 9 is 72
Next, find the equivalent fraction of both fractional numbers with denominator 72 - For the 1st fraction, since 8 × 9 = 72,
30/8 = 30 × 9/8 × 9 = 270/72 - Likewise, for the 2nd fraction, since 9 × 8 = 72,
21/9 = 21 × 8/9 × 8 = 168/72 - Subtract the two like fractions:
270/72 - 168/72 = 270 - 168/72 = 102/72 - After reducing the fraction, the answer is 17/12
- In mixed form: 15/12
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/8-21/9 30/8-42/9 30/16-21/9 30/8-21/18 90/8-21/9 30/8-63/9 30/24-21/9 30/8-21/27 30/40-21/9 30/8-21/45 30/56-21/9 30/8-21/63