Subtract 15/12 from 30/42
1st number: 30/42, 2nd number: 1 3/12
30/42 - 15/12 is -15/28.
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,
15/12 = 15 × 7/12 × 7 = 105/84 - Subtract the two like fractions:
60/84 - 105/84 = 60 - 105/84 = -45/84 - After reducing the fraction, the answer is -15/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/42-15/12 30/42-30/12 30/84-15/12 30/42-15/24 90/42-15/12 30/42-45/12 30/42-15/36 30/42-75/12 30/42-15/60 30/42-15/84