Subtract 75/81 from 3/21
3/21 - 75/81 is -148/189.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 81 is 567
Next, find the equivalent fraction of both fractional numbers with denominator 567 - For the 1st fraction, since 21 × 27 = 567,
3/21 = 3 × 27/21 × 27 = 81/567 - Likewise, for the 2nd fraction, since 81 × 7 = 567,
75/81 = 75 × 7/81 × 7 = 525/567 - Subtract the two like fractions:
81/567 - 525/567 = 81 - 525/567 = -444/567 - After reducing the fraction, the answer is -148/189
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/21-75/81 3/42-75/81 9/21-75/81 3/63-75/81 15/21-75/81