Subtract 21/81 from 25/20
1st number: 1 5/20, 2nd number: 21/81
25/20 - 21/81 is 107/108.
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,
25/20 = 25 × 81/20 × 81 = 2025/1620 - Likewise, for the 2nd fraction, since 81 × 20 = 1620,
21/81 = 21 × 20/81 × 20 = 420/1620 - Subtract the two like fractions:
2025/1620 - 420/1620 = 2025 - 420/1620 = 1605/1620 - After reducing the fraction, the answer is 107/108
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 50/20-21/81 25/20-42/81 25/40-21/81 75/20-21/81 25/20-63/81 25/60-21/81