Subtract 21/8 from 12/9
1st number: 1 3/9, 2nd number: 2 5/8
12/9 - 21/8 is -31/24.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 9 and 8 is 72
Next, find the equivalent fraction of both fractional numbers with denominator 72 - For the 1st fraction, since 9 × 8 = 72,
12/9 = 12 × 8/9 × 8 = 96/72 - Likewise, for the 2nd fraction, since 8 × 9 = 72,
21/8 = 21 × 9/8 × 9 = 189/72 - Subtract the two like fractions:
96/72 - 189/72 = 96 - 189/72 = -93/72 - After reducing the fraction, the answer is -31/24
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/9-21/8 12/9-42/8 12/18-21/8 12/9-21/16 36/9-21/8 12/9-63/8 12/27-21/8 12/9-21/24 60/9-21/8 12/45-21/8 12/9-21/40 84/9-21/8 12/63-21/8 12/9-21/56