Add 42/15 and 21/9
1st number: 2 12/15, 2nd number: 2 3/9
42/15 + 21/9 is 77/15.
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,
42/15 = 42 × 3/15 × 3 = 126/45 - Likewise, for the 2nd fraction, since 9 × 5 = 45,
21/9 = 21 × 5/9 × 5 = 105/45 - Add the two like fractions:
126/45 + 105/45 = 126 + 105/45 = 231/45 - 231/45 simplified gives 77/15
- So, 42/15 + 21/9 = 77/15
In mixed form: 52/15
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/15+21/9 42/15+42/9 42/30+21/9 42/15+21/18 42/15+63/9 42/45+21/9 42/15+21/27 42/75+21/9 42/15+21/45 42/15+21/63