Subtract 10/5 from 7/81
1st number: 7/81, 2nd number: 2 0/5
7/81 - 10/5 is -155/81.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 5 is 405
Next, find the equivalent fraction of both fractional numbers with denominator 405 - For the 1st fraction, since 81 × 5 = 405,
7/81 = 7 × 5/81 × 5 = 35/405 - Likewise, for the 2nd fraction, since 5 × 81 = 405,
10/5 = 10 × 81/5 × 81 = 810/405 - Subtract the two like fractions:
35/405 - 810/405 = 35 - 810/405 = -775/405 - After reducing the fraction, the answer is -155/81
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/81-10/5 7/81-20/5 21/81-10/5 7/81-30/5 7/81-10/15 35/81-10/5 7/81-50/5 7/81-10/25 49/81-10/5 7/81-70/5 7/81-10/35