Subtract 40/18 from 81/30
1st number: 2 21/30, 2nd number: 2 4/18
81/30 - 40/18 is 43/90.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 18 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 30 × 3 = 90,
81/30 = 81 × 3/30 × 3 = 243/90 - Likewise, for the 2nd fraction, since 18 × 5 = 90,
40/18 = 40 × 5/18 × 5 = 200/90 - Subtract the two like fractions:
243/90 - 200/90 = 243 - 200/90 = 43/90
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 81/30-80/18 81/60-40/18 81/30-40/36 81/90-40/18 81/30-40/54 81/30-40/90