Subtract 81/90 from 2/5
2/5 - 81/90 is -1/2.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 5 and 90 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 5 × 18 = 90,
2/5 = 2 × 18/5 × 18 = 36/90 - Likewise, for the 2nd fraction, since 90 × 1 = 90,
81/90 = 81 × 1/90 × 1 = 81/90 - Subtract the two like fractions:
36/90 - 81/90 = 36 - 81/90 = -45/90 - After reducing the fraction, the answer is -1/2
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 4/5-81/90 2/10-81/90 6/5-81/90 2/15-81/90 10/5-81/90 2/25-81/90 14/5-81/90 2/35-81/90