Subtract 3/21 from 42/12
1st number: 3 6/12, 2nd number: 3/21
42/12 - 3/21 is 47/14.
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,
3/21 = 3 × 4/21 × 4 = 12/84 - Subtract the two like fractions:
294/84 - 12/84 = 294 - 12/84 = 282/84 - After reducing the fraction, the answer is 47/14
- In mixed form: 35/14
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/12-3/21 42/12-6/21 42/24-3/21 42/12-3/42 42/12-9/21 42/36-3/21 42/12-3/63 42/12-15/21 42/60-3/21 42/84-3/21