Add 28/21 and 4/15
1st number: 1 7/21, 2nd number: 4/15
28/21 + 4/15 is 8/5.
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,
28/21 = 28 × 5/21 × 5 = 140/105 - Likewise, for the 2nd fraction, since 15 × 7 = 105,
4/15 = 4 × 7/15 × 7 = 28/105 - Add the two like fractions:
140/105 + 28/105 = 140 + 28/105 = 168/105 - 168/105 simplified gives 8/5
- So, 28/21 + 4/15 = 8/5
In mixed form: 13/5
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/21+4/15 28/21+8/15 28/42+4/15 28/21+4/30 84/21+4/15 28/21+12/15 28/63+4/15 28/21+4/45 28/21+20/15 28/21+4/75 28/21+28/15