Subtract 18/7 from 81/40
1st number: 2 1/40, 2nd number: 2 4/7
81/40 - 18/7 is -153/280.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 7 is 280
Next, find the equivalent fraction of both fractional numbers with denominator 280 - For the 1st fraction, since 40 × 7 = 280,
81/40 = 81 × 7/40 × 7 = 567/280 - Likewise, for the 2nd fraction, since 7 × 40 = 280,
18/7 = 18 × 40/7 × 40 = 720/280 - Subtract the two like fractions:
567/280 - 720/280 = 567 - 720/280 = -153/280
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 81/40-36/7 81/80-18/7 81/40-18/14 81/40-54/7 81/40-18/21 81/40-90/7 81/40-18/35 81/40-18/49