Subtract 21/5 from 45/4
1st number: 11 1/4, 2nd number: 4 1/5
45/4 - 21/5 is 141/20.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 4 and 5 is 20
Next, find the equivalent fraction of both fractional numbers with denominator 20 - For the 1st fraction, since 4 × 5 = 20,
45/4 = 45 × 5/4 × 5 = 225/20 - Likewise, for the 2nd fraction, since 5 × 4 = 20,
21/5 = 21 × 4/5 × 4 = 84/20 - Subtract the two like fractions:
225/20 - 84/20 = 225 - 84/20 = 141/20 - In mixed form: 71/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/4-21/5 45/4-42/5 45/8-21/5 45/4-21/10 45/4-63/5 45/12-21/5 45/4-21/15 45/20-21/5 45/4-21/25 45/28-21/5 45/4-21/35