Subtract 16/81 from 9/90
9/90 - 16/81 is -79/810.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 81 is 810
Next, find the equivalent fraction of both fractional numbers with denominator 810 - For the 1st fraction, since 90 × 9 = 810,
9/90 = 9 × 9/90 × 9 = 81/810 - Likewise, for the 2nd fraction, since 81 × 10 = 810,
16/81 = 16 × 10/81 × 10 = 160/810 - Subtract the two like fractions:
81/810 - 160/810 = 81 - 160/810 = -79/810
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 18/90-16/81 9/90-32/81 27/90-16/81 9/90-48/81 45/90-16/81 9/90-80/81 63/90-16/81