Add 9/21 and 9/12
9/21 + 9/12 is 33/28.
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,
9/21 = 9 × 4/21 × 4 = 36/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
9/12 = 9 × 7/12 × 7 = 63/84 - Add the two like fractions:
36/84 + 63/84 = 36 + 63/84 = 99/84 - 99/84 simplified gives 33/28
- So, 9/21 + 9/12 = 33/28
In mixed form: 15/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 18/21+9/12 9/21+18/12 9/42+9/12 9/21+9/24 27/21+9/12 9/21+27/12 9/63+9/12 9/21+9/36 45/21+9/12 9/21+45/12 9/21+9/60 63/21+9/12 9/21+63/12 9/21+9/84