Add 15/7 and 21/9
1st number: 2 1/7, 2nd number: 2 3/9
15/7 + 21/9 is 94/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 7 and 9 is 63
Next, find the equivalent fraction of both fractional numbers with denominator 63 - For the 1st fraction, since 7 × 9 = 63,
15/7 = 15 × 9/7 × 9 = 135/63 - Likewise, for the 2nd fraction, since 9 × 7 = 63,
21/9 = 21 × 7/9 × 7 = 147/63 - Add the two like fractions:
135/63 + 147/63 = 135 + 147/63 = 282/63 - 282/63 simplified gives 94/21
- So, 15/7 + 21/9 = 94/21
In mixed form: 410/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/7+21/9 15/7+42/9 15/14+21/9 15/7+21/18 45/7+21/9 15/7+63/9 15/21+21/9 15/7+21/27 75/7+21/9 15/35+21/9 15/7+21/45 15/49+21/9 15/7+21/63