Subtract 30/81 from 20/12
1st number: 1 8/12, 2nd number: 30/81
20/12 - 30/81 is 35/27.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 81 is 324
Next, find the equivalent fraction of both fractional numbers with denominator 324 - For the 1st fraction, since 12 × 27 = 324,
20/12 = 20 × 27/12 × 27 = 540/324 - Likewise, for the 2nd fraction, since 81 × 4 = 324,
30/81 = 30 × 4/81 × 4 = 120/324 - Subtract the two like fractions:
540/324 - 120/324 = 540 - 120/324 = 420/324 - After reducing the fraction, the answer is 35/27
- In mixed form: 18/27
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/12-30/81 20/12-60/81 20/24-30/81 60/12-30/81 20/12-90/81 20/36-30/81 20/60-30/81 20/84-30/81