Add 20/15 and 21/9
1st number: 1 5/15, 2nd number: 2 3/9
20/15 + 21/9 is 11/3.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 9 is 45
Next, find the equivalent fraction of both fractional numbers with denominator 45 - For the 1st fraction, since 15 × 3 = 45,
20/15 = 20 × 3/15 × 3 = 60/45 - Likewise, for the 2nd fraction, since 9 × 5 = 45,
21/9 = 21 × 5/9 × 5 = 105/45 - Add the two like fractions:
60/45 + 105/45 = 60 + 105/45 = 165/45 - 165/45 simplified gives 11/3
- So, 20/15 + 21/9 = 11/3
In mixed form: 32/3
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/15+21/9 20/15+42/9 20/30+21/9 20/15+21/18 60/15+21/9 20/15+63/9 20/45+21/9 20/15+21/27 20/75+21/9 20/15+21/45 20/15+21/63