Add 15/30 and 15/21
15/30 + 15/21 is 17/14.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 21 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 30 × 7 = 210,
15/30 = 15 × 7/30 × 7 = 105/210 - Likewise, for the 2nd fraction, since 21 × 10 = 210,
15/21 = 15 × 10/21 × 10 = 150/210 - Add the two like fractions:
105/210 + 150/210 = 105 + 150/210 = 255/210 - 255/210 simplified gives 17/14
- So, 15/30 + 15/21 = 17/14
In mixed form: 13/14
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 15/30+30/21 15/60+15/21 15/30+15/42 45/30+15/21 15/30+45/21 15/90+15/21 15/30+15/63 75/30+15/21 15/30+75/21