Subtract 20/40 from 21/15
1st number: 1 6/15, 2nd number: 20/40
21/15 - 20/40 is 9/10.
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,
21/15 = 21 × 8/15 × 8 = 168/120 - Likewise, for the 2nd fraction, since 40 × 3 = 120,
20/40 = 20 × 3/40 × 3 = 60/120 - Subtract the two like fractions:
168/120 - 60/120 = 168 - 60/120 = 108/120 - After reducing the fraction, the answer is 9/10
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/15-20/40 21/30-20/40 21/15-20/80 63/15-20/40 21/15-60/40 21/45-20/40 21/75-20/40