Add 21/15 and 12/84
1st number: 1 6/15, 2nd number: 12/84
21/15 + 12/84 is 54/35.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 84 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 15 × 28 = 420,
21/15 = 21 × 28/15 × 28 = 588/420 - Likewise, for the 2nd fraction, since 84 × 5 = 420,
12/84 = 12 × 5/84 × 5 = 60/420 - Add the two like fractions:
588/420 + 60/420 = 588 + 60/420 = 648/420 - 648/420 simplified gives 54/35
- So, 21/15 + 12/84 = 54/35
In mixed form: 119/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/15+12/84 21/15+24/84 21/30+12/84 63/15+12/84 21/15+36/84 21/45+12/84 21/15+60/84 21/75+12/84