Subtract 21/5 from 81/63
1st number: 1 18/63, 2nd number: 4 1/5
81/63 - 21/5 is -102/35.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 63 and 5 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 63 × 5 = 315,
81/63 = 81 × 5/63 × 5 = 405/315 - Likewise, for the 2nd fraction, since 5 × 63 = 315,
21/5 = 21 × 63/5 × 63 = 1323/315 - Subtract the two like fractions:
405/315 - 1323/315 = 405 - 1323/315 = -918/315 - After reducing the fraction, the answer is -102/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 81/63-42/5 81/63-21/10 81/63-63/5 81/63-21/15 81/63-21/25 81/63-21/35