Add 15/21 and 7/15
15/21 + 7/15 is 124/105.
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,
15/21 = 15 × 5/21 × 5 = 75/105 - Likewise, for the 2nd fraction, since 15 × 7 = 105,
7/15 = 7 × 7/15 × 7 = 49/105 - Add the two like fractions:
75/105 + 49/105 = 75 + 49/105 = 124/105 - So, 15/21 + 7/15 = 124/105
In mixed form: 119/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/21+7/15 15/21+14/15 15/42+7/15 15/21+7/30 45/21+7/15 15/21+21/15 15/63+7/15 15/21+7/45 75/21+7/15 15/21+35/15 15/21+7/75 15/21+49/15