Subtract 30/12 from 21/27
1st number: 21/27, 2nd number: 2 6/12
21/27 - 30/12 is -31/18.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 27 and 12 is 108
Next, find the equivalent fraction of both fractional numbers with denominator 108 - For the 1st fraction, since 27 × 4 = 108,
21/27 = 21 × 4/27 × 4 = 84/108 - Likewise, for the 2nd fraction, since 12 × 9 = 108,
30/12 = 30 × 9/12 × 9 = 270/108 - Subtract the two like fractions:
84/108 - 270/108 = 84 - 270/108 = -186/108 - After reducing the fraction, the answer is -31/18
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/27-30/12 21/27-60/12 21/54-30/12 21/27-30/24 63/27-30/12 21/27-90/12 21/81-30/12 21/27-30/36 21/27-30/60 21/27-30/84