Subtract 81/45 from 21/5
1st number: 4 1/5, 2nd number: 1 36/45
21/5 - 81/45 is 12/5.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 5 and 45 is 45
Next, find the equivalent fraction of both fractional numbers with denominator 45 - For the 1st fraction, since 5 × 9 = 45,
21/5 = 21 × 9/5 × 9 = 189/45 - Likewise, for the 2nd fraction, since 45 × 1 = 45,
81/45 = 81 × 1/45 × 1 = 81/45 - Subtract the two like fractions:
189/45 - 81/45 = 189 - 81/45 = 108/45 - After reducing the fraction, the answer is 12/5
- In mixed form: 22/5
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/5-81/45 21/10-81/45 21/5-81/90 63/5-81/45 21/15-81/45 21/25-81/45 21/35-81/45