Subtract 12/27 from 7/42
7/42 - 12/27 is -5/18.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 27 is 378
Next, find the equivalent fraction of both fractional numbers with denominator 378 - For the 1st fraction, since 42 × 9 = 378,
7/42 = 7 × 9/42 × 9 = 63/378 - Likewise, for the 2nd fraction, since 27 × 14 = 378,
12/27 = 12 × 14/27 × 14 = 168/378 - Subtract the two like fractions:
63/378 - 168/378 = 63 - 168/378 = -105/378 - After reducing the fraction, the answer is -5/18
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/42-12/27 7/42-24/27 7/84-12/27 7/42-12/54 21/42-12/27 7/42-36/27 7/42-12/81 35/42-12/27 7/42-60/27 49/42-12/27 7/42-84/27