Subtract 40/15 from 40/21
1st number: 1 19/21, 2nd number: 2 10/15
40/21 - 40/15 is -16/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 15 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 21 × 5 = 105,
40/21 = 40 × 5/21 × 5 = 200/105 - Likewise, for the 2nd fraction, since 15 × 7 = 105,
40/15 = 40 × 7/15 × 7 = 280/105 - Subtract the two like fractions:
200/105 - 280/105 = 200 - 280/105 = -80/105 - After reducing the fraction, the answer is -16/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/21-40/15 40/21-80/15 40/42-40/15 40/21-40/30 40/63-40/15 40/21-40/45 40/21-40/75