Add 5/15 and 6/21
5/15 + 6/21 is 13/21.
Steps for adding 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,
5/15 = 5 × 7/15 × 7 = 35/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
6/21 = 6 × 5/21 × 5 = 30/105 - Add the two like fractions:
35/105 + 30/105 = 35 + 30/105 = 65/105 - 65/105 simplified gives 13/21
- So, 5/15 + 6/21 = 13/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 10/15+6/21 5/15+12/21 5/30+6/21 5/15+6/42 5/15+18/21 5/45+6/21 5/15+6/63 25/15+6/21 5/15+30/21 5/75+6/21 35/15+6/21 5/15+42/21