Subtract 45/81 from 21/20
1st number: 1 1/20, 2nd number: 45/81
21/20 - 45/81 is 89/180.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 81 is 1620
Next, find the equivalent fraction of both fractional numbers with denominator 1620 - For the 1st fraction, since 20 × 81 = 1620,
21/20 = 21 × 81/20 × 81 = 1701/1620 - Likewise, for the 2nd fraction, since 81 × 20 = 1620,
45/81 = 45 × 20/81 × 20 = 900/1620 - Subtract the two like fractions:
1701/1620 - 900/1620 = 1701 - 900/1620 = 801/1620 - After reducing the fraction, the answer is 89/180
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/20-45/81 21/20-90/81 21/40-45/81 63/20-45/81 21/60-45/81