Subtract 21/40 from 10/15
10/15 - 21/40 is 17/120.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 40 is 120
Next, find the equivalent fraction of both fractional numbers with denominator 120 - For the 1st fraction, since 15 × 8 = 120,
10/15 = 10 × 8/15 × 8 = 80/120 - Likewise, for the 2nd fraction, since 40 × 3 = 120,
21/40 = 21 × 3/40 × 3 = 63/120 - Subtract the two like fractions:
80/120 - 63/120 = 80 - 63/120 = 17/120
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 20/15-21/40 10/15-42/40 10/30-21/40 10/15-21/80 30/15-21/40 10/15-63/40 10/45-21/40 50/15-21/40 10/75-21/40 70/15-21/40