Subtract 4/21 from 42/12
1st number: 3 6/12, 2nd number: 4/21
42/12 - 4/21 is 139/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 12 × 7 = 84,
42/12 = 42 × 7/12 × 7 = 294/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
4/21 = 4 × 4/21 × 4 = 16/84 - Subtract the two like fractions:
294/84 - 16/84 = 294 - 16/84 = 278/84 - After reducing the fraction, the answer is 139/42
- In mixed form: 313/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/12-4/21 42/12-8/21 42/24-4/21 42/12-4/42 42/12-12/21 42/36-4/21 42/12-4/63 42/12-20/21 42/60-4/21 42/12-28/21 42/84-4/21