Subtract 3/12 from 5/42
5/42 - 3/12 is -11/84.
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,
5/42 = 5 × 2/42 × 2 = 10/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
3/12 = 3 × 7/12 × 7 = 21/84 - Subtract the two like fractions:
10/84 - 21/84 = 10 - 21/84 = -11/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 10/42-3/12 5/42-6/12 5/84-3/12 5/42-3/24 15/42-3/12 5/42-9/12 5/42-3/36 25/42-3/12 5/42-15/12 5/42-3/60 35/42-3/12 5/42-21/12 5/42-3/84