Add 5/21 and 28/15
1st number: 5/21, 2nd number: 1 13/15
5/21 + 28/15 is 221/105.
Steps for adding 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,
5/21 = 5 × 5/21 × 5 = 25/105 - Likewise, for the 2nd fraction, since 15 × 7 = 105,
28/15 = 28 × 7/15 × 7 = 196/105 - Add the two like fractions:
25/105 + 196/105 = 25 + 196/105 = 221/105 - So, 5/21 + 28/15 = 221/105
In mixed form: 211/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 10/21+28/15 5/21+56/15 5/42+28/15 5/21+28/30 15/21+28/15 5/21+84/15 5/63+28/15 5/21+28/45 25/21+28/15 5/21+28/75 35/21+28/15