Add 28/15 and 28/21
1st number: 1 13/15, 2nd number: 1 7/21
28/15 + 28/21 is 16/5.
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,
28/15 = 28 × 7/15 × 7 = 196/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
28/21 = 28 × 5/21 × 5 = 140/105 - Add the two like fractions:
196/105 + 140/105 = 196 + 140/105 = 336/105 - 336/105 simplified gives 16/5
- So, 28/15 + 28/21 = 16/5
In mixed form: 31/5
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/15+28/21 28/15+56/21 28/30+28/21 28/15+28/42 84/15+28/21 28/15+84/21 28/45+28/21 28/15+28/63 28/75+28/21