Add 80/15 and 18/21
1st number: 5 5/15, 2nd number: 18/21
80/15 + 18/21 is 130/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 21 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 15 × 7 = 105,
80/15 = 80 × 7/15 × 7 = 560/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
18/21 = 18 × 5/21 × 5 = 90/105 - Add the two like fractions:
560/105 + 90/105 = 560 + 90/105 = 650/105 - 650/105 simplified gives 130/21
- So, 80/15 + 18/21 = 130/21
In mixed form: 64/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/15+36/21 80/30+18/21 80/15+18/42 80/15+54/21 80/45+18/21 80/15+18/63 80/15+90/21 80/75+18/21