Add 15/21 and 8/12
15/21 + 8/12 is 29/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 12 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 21 × 4 = 84,
15/21 = 15 × 4/21 × 4 = 60/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
8/12 = 8 × 7/12 × 7 = 56/84 - Add the two like fractions:
60/84 + 56/84 = 60 + 56/84 = 116/84 - 116/84 simplified gives 29/21
- So, 15/21 + 8/12 = 29/21
In mixed form: 18/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/21+8/12 15/21+16/12 15/42+8/12 15/21+8/24 45/21+8/12 15/21+24/12 15/63+8/12 15/21+8/36 75/21+8/12 15/21+40/12 15/21+8/60 15/21+56/12 15/21+8/84