Subtract 42/5 from 21/2
1st number: 10 1/2, 2nd number: 8 2/5
21/2 - 42/5 is 21/10.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 2 and 5 is 10
Next, find the equivalent fraction of both fractional numbers with denominator 10 - For the 1st fraction, since 2 × 5 = 10,
21/2 = 21 × 5/2 × 5 = 105/10 - Likewise, for the 2nd fraction, since 5 × 2 = 10,
42/5 = 42 × 2/5 × 2 = 84/10 - Subtract the two like fractions:
105/10 - 84/10 = 105 - 84/10 = 21/10 - In mixed form: 21/10
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/2-42/5 21/2-84/5 21/4-42/5 21/2-42/10 63/2-42/5 21/6-42/5 21/2-42/15 21/10-42/5 21/2-42/25 21/14-42/5 21/2-42/35