Subtract 42/10 from 21/15
1st number: 1 6/15, 2nd number: 4 2/10
21/15 - 42/10 is -14/5.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 10 is 30
Next, find the equivalent fraction of both fractional numbers with denominator 30 - For the 1st fraction, since 15 × 2 = 30,
21/15 = 21 × 2/15 × 2 = 42/30 - Likewise, for the 2nd fraction, since 10 × 3 = 30,
42/10 = 42 × 3/10 × 3 = 126/30 - Subtract the two like fractions:
42/30 - 126/30 = 42 - 126/30 = -84/30 - After reducing the fraction, the answer is -14/5
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/15-42/10 21/15-84/10 21/30-42/10 21/15-42/20 63/15-42/10 21/45-42/10 21/15-42/30 21/75-42/10 21/15-42/50 21/15-42/70