Subtract 21/10 from 15/42
1st number: 15/42, 2nd number: 2 1/10
15/42 - 21/10 is -61/35.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 10 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 42 × 5 = 210,
15/42 = 15 × 5/42 × 5 = 75/210 - Likewise, for the 2nd fraction, since 10 × 21 = 210,
21/10 = 21 × 21/10 × 21 = 441/210 - Subtract the two like fractions:
75/210 - 441/210 = 75 - 441/210 = -366/210 - After reducing the fraction, the answer is -61/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/42-21/10 15/42-42/10 15/84-21/10 15/42-21/20 45/42-21/10 15/42-63/10 15/42-21/30 75/42-21/10 15/42-21/50 15/42-21/70