Subtract 21/8 from 10/20
1st number: 10/20, 2nd number: 2 5/8
10/20 - 21/8 is -17/8.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 8 is 40
Next, find the equivalent fraction of both fractional numbers with denominator 40 - For the 1st fraction, since 20 × 2 = 40,
10/20 = 10 × 2/20 × 2 = 20/40 - Likewise, for the 2nd fraction, since 8 × 5 = 40,
21/8 = 21 × 5/8 × 5 = 105/40 - Subtract the two like fractions:
20/40 - 105/40 = 20 - 105/40 = -85/40 - After reducing the fraction, the answer is -17/8
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 10/20-42/8 10/40-21/8 10/20-21/16 30/20-21/8 10/20-63/8 10/60-21/8 10/20-21/24 50/20-21/8 10/20-21/40 70/20-21/8 10/20-21/56