Subtract 15/42 from 3/12
3/12 - 15/42 is -3/28.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 42 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 12 × 7 = 84,
3/12 = 3 × 7/12 × 7 = 21/84 - Likewise, for the 2nd fraction, since 42 × 2 = 84,
15/42 = 15 × 2/42 × 2 = 30/84 - Subtract the two like fractions:
21/84 - 30/84 = 21 - 30/84 = -9/84 - After reducing the fraction, the answer is -3/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/12-15/42 3/12-30/42 3/24-15/42 3/12-15/84 9/12-15/42 3/12-45/42 3/36-15/42 15/12-15/42 3/12-75/42 3/60-15/42 21/12-15/42 3/84-15/42