Subtract 40/30 from 21/15
1st number: 1 6/15, 2nd number: 1 10/30
21/15 - 40/30 is 1/15.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 30 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 30 × 1 = 30,
40/30 = 40 × 1/30 × 1 = 40/30 - Subtract the two like fractions:
42/30 - 40/30 = 42 - 40/30 = 2/30 - After reducing the fraction, the answer is 1/15
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/15-40/30 21/15-80/30 21/30-40/30 21/15-40/60 63/15-40/30 21/45-40/30 21/15-40/90 21/75-40/30