Subtract 21/10 from 15/9
1st number: 1 6/9, 2nd number: 2 1/10
15/9 - 21/10 is -13/30.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 9 and 10 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 9 × 10 = 90,
15/9 = 15 × 10/9 × 10 = 150/90 - Likewise, for the 2nd fraction, since 10 × 9 = 90,
21/10 = 21 × 9/10 × 9 = 189/90 - Subtract the two like fractions:
150/90 - 189/90 = 150 - 189/90 = -39/90 - After reducing the fraction, the answer is -13/30
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/9-21/10 15/9-42/10 15/18-21/10 15/9-21/20 45/9-21/10 15/9-63/10 15/27-21/10 15/9-21/30 75/9-21/10 15/45-21/10 15/9-21/50 15/63-21/10 15/9-21/70