Add 12/5 and 21/9
1st number: 2 2/5, 2nd number: 2 3/9
12/5 + 21/9 is 71/15.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 5 and 9 is 45
Next, find the equivalent fraction of both fractional numbers with denominator 45 - For the 1st fraction, since 5 × 9 = 45,
12/5 = 12 × 9/5 × 9 = 108/45 - Likewise, for the 2nd fraction, since 9 × 5 = 45,
21/9 = 21 × 5/9 × 5 = 105/45 - Add the two like fractions:
108/45 + 105/45 = 108 + 105/45 = 213/45 - 213/45 simplified gives 71/15
- So, 12/5 + 21/9 = 71/15
In mixed form: 411/15
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/5+21/9 12/5+42/9 12/10+21/9 12/5+21/18 36/5+21/9 12/5+63/9 12/15+21/9 12/5+21/27 60/5+21/9 12/25+21/9 12/5+21/45 84/5+21/9 12/35+21/9 12/5+21/63