Subtract 5/30 from 7/81
7/81 - 5/30 is -13/162.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 30 is 810
Next, find the equivalent fraction of both fractional numbers with denominator 810 - For the 1st fraction, since 81 × 10 = 810,
7/81 = 7 × 10/81 × 10 = 70/810 - Likewise, for the 2nd fraction, since 30 × 27 = 810,
5/30 = 5 × 27/30 × 27 = 135/810 - Subtract the two like fractions:
70/810 - 135/810 = 70 - 135/810 = -65/810 - After reducing the fraction, the answer is -13/162
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/81-5/30 7/81-10/30 7/81-5/60 21/81-5/30 7/81-15/30 7/81-5/90 35/81-5/30 7/81-25/30 49/81-5/30 7/81-35/30