Add 80/21 and 4/15
1st number: 3 17/21, 2nd number: 4/15
80/21 + 4/15 is 428/105.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 15 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 21 × 5 = 105,
80/21 = 80 × 5/21 × 5 = 400/105 - Likewise, for the 2nd fraction, since 15 × 7 = 105,
4/15 = 4 × 7/15 × 7 = 28/105 - Add the two like fractions:
400/105 + 28/105 = 400 + 28/105 = 428/105 - So, 80/21 + 4/15 = 428/105
In mixed form: 48/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/21+8/15 80/42+4/15 80/21+4/30 80/21+12/15 80/63+4/15 80/21+4/45 80/21+20/15 80/21+4/75 80/21+28/15