Add 15/21 and 21/15
1st number: 15/21, 2nd number: 1 6/15
15/21 + 21/15 is 74/35.
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,
21/15 = 21 × 7/15 × 7 = 147/105 - Add the two like fractions:
75/105 + 147/105 = 75 + 147/105 = 222/105 - 222/105 simplified gives 74/35
- So, 15/21 + 21/15 = 74/35
In mixed form: 24/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/21+21/15 15/21+42/15 15/42+21/15 15/21+21/30 45/21+21/15 15/21+63/15 15/63+21/15 15/21+21/45 75/21+21/15 15/21+21/75