Subtract 12/21 from 8/15
8/15 - 12/21 is -4/105.
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,
8/15 = 8 × 7/15 × 7 = 56/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
12/21 = 12 × 5/21 × 5 = 60/105 - Subtract the two like fractions:
56/105 - 60/105 = 56 - 60/105 = -4/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 16/15-12/21 8/15-24/21 8/30-12/21 8/15-12/42 24/15-12/21 8/15-36/21 8/45-12/21 8/15-12/63 40/15-12/21 8/15-60/21 8/75-12/21 56/15-12/21 8/15-84/21