Subtract 40/21 from 9/15
1st number: 9/15, 2nd number: 1 19/21
9/15 - 40/21 is -137/105.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 21 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 15 × 7 = 105,
9/15 = 9 × 7/15 × 7 = 63/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
40/21 = 40 × 5/21 × 5 = 200/105 - Subtract the two like fractions:
63/105 - 200/105 = 63 - 200/105 = -137/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 18/15-40/21 9/15-80/21 9/30-40/21 9/15-40/42 27/15-40/21 9/45-40/21 9/15-40/63 45/15-40/21 9/75-40/21 63/15-40/21