Subtract 21/42 from 30/12
1st number: 2 6/12, 2nd number: 21/42
30/12 - 21/42 is 2/1.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 42 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 12 × 7 = 84,
30/12 = 30 × 7/12 × 7 = 210/84 - Likewise, for the 2nd fraction, since 42 × 2 = 84,
21/42 = 21 × 2/42 × 2 = 42/84 - Subtract the two like fractions:
210/84 - 42/84 = 210 - 42/84 = 168/84 - After reducing the fraction, the answer is 2/1
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/12-21/42 30/24-21/42 30/12-21/84 90/12-21/42 30/12-63/42 30/36-21/42 30/60-21/42 30/84-21/42