Subtract 7/90 from 6/81
6/81 - 7/90 is -1/270.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 90 is 810
Next, find the equivalent fraction of both fractional numbers with denominator 810 - For the 1st fraction, since 81 × 10 = 810,
6/81 = 6 × 10/81 × 10 = 60/810 - Likewise, for the 2nd fraction, since 90 × 9 = 810,
7/90 = 7 × 9/90 × 9 = 63/810 - Subtract the two like fractions:
60/810 - 63/810 = 60 - 63/810 = -3/810 - After reducing the fraction, the answer is -1/270
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 12/81-7/90 6/81-14/90 18/81-7/90 6/81-21/90 30/81-7/90 6/81-35/90 42/81-7/90 6/81-49/90