Add 81/84 and 42/30
1st number: 81/84, 2nd number: 1 12/30
81/84 + 42/30 is 331/140.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 30 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 84 × 5 = 420,
81/84 = 81 × 5/84 × 5 = 405/420 - Likewise, for the 2nd fraction, since 30 × 14 = 420,
42/30 = 42 × 14/30 × 14 = 588/420 - Add the two like fractions:
405/420 + 588/420 = 405 + 588/420 = 993/420 - 993/420 simplified gives 331/140
- So, 81/84 + 42/30 = 331/140
In mixed form: 251/140
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 81/84+84/30 81/84+42/60 81/84+42/90