Subtract 28/12 from 30/42
1st number: 30/42, 2nd number: 2 4/12
30/42 - 28/12 is -34/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 12 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 42 × 2 = 84,
30/42 = 30 × 2/42 × 2 = 60/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
28/12 = 28 × 7/12 × 7 = 196/84 - Subtract the two like fractions:
60/84 - 196/84 = 60 - 196/84 = -136/84 - After reducing the fraction, the answer is -34/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/42-28/12 30/42-56/12 30/84-28/12 30/42-28/24 90/42-28/12 30/42-84/12 30/42-28/36 30/42-28/60 30/42-28/84