Add 42/81 and 9/12
42/81 + 9/12 is 137/108.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 12 is 324
Next, find the equivalent fraction of both fractional numbers with denominator 324 - For the 1st fraction, since 81 × 4 = 324,
42/81 = 42 × 4/81 × 4 = 168/324 - Likewise, for the 2nd fraction, since 12 × 27 = 324,
9/12 = 9 × 27/12 × 27 = 243/324 - Add the two like fractions:
168/324 + 243/324 = 168 + 243/324 = 411/324 - 411/324 simplified gives 137/108
- So, 42/81 + 9/12 = 137/108
In mixed form: 129/108
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/81+9/12 42/81+18/12 42/81+9/24 42/81+27/12 42/81+9/36 42/81+45/12 42/81+9/60 42/81+63/12 42/81+9/84