Subtract 40/21 from 15/10
1st number: 1 5/10, 2nd number: 1 19/21
15/10 - 40/21 is -17/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 10 and 21 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 10 × 21 = 210,
15/10 = 15 × 21/10 × 21 = 315/210 - Likewise, for the 2nd fraction, since 21 × 10 = 210,
40/21 = 40 × 10/21 × 10 = 400/210 - Subtract the two like fractions:
315/210 - 400/210 = 315 - 400/210 = -85/210 - After reducing the fraction, the answer is -17/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/10-40/21 15/10-80/21 15/20-40/21 15/10-40/42 45/10-40/21 15/30-40/21 15/10-40/63 75/10-40/21 15/50-40/21 15/70-40/21