Subtract 21/30 from 42/15
1st number: 2 12/15, 2nd number: 21/30
42/15 - 21/30 is 21/10.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 30 is 30
Next, find the equivalent fraction of both fractional numbers with denominator 30 - For the 1st fraction, since 15 × 2 = 30,
42/15 = 42 × 2/15 × 2 = 84/30 - Likewise, for the 2nd fraction, since 30 × 1 = 30,
21/30 = 21 × 1/30 × 1 = 21/30 - Subtract the two like fractions:
84/30 - 21/30 = 84 - 21/30 = 63/30 - After reducing the fraction, the answer is 21/10
- In mixed form: 21/10
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/15-21/30 42/15-42/30 42/30-21/30 42/15-21/60 42/15-63/30 42/45-21/30 42/15-21/90 42/75-21/30