Subtract 2/12 from 21/42
21/42 - 2/12 is 1/3.
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,
21/42 = 21 × 2/42 × 2 = 42/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
2/12 = 2 × 7/12 × 7 = 14/84 - Subtract the two like fractions:
42/84 - 14/84 = 42 - 14/84 = 28/84 - After reducing the fraction, the answer is 1/3
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 21/42-4/12 21/84-2/12 21/42-2/24 63/42-2/12 21/42-6/12 21/42-2/36 21/42-10/12 21/42-2/60 21/42-14/12 21/42-2/84