Add 12/15 and 15/21
12/15 + 15/21 is 53/35.
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,
12/15 = 12 × 7/15 × 7 = 84/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
15/21 = 15 × 5/21 × 5 = 75/105 - Add the two like fractions:
84/105 + 75/105 = 84 + 75/105 = 159/105 - 159/105 simplified gives 53/35
- So, 12/15 + 15/21 = 53/35
In mixed form: 118/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/15+15/21 12/15+30/21 12/30+15/21 12/15+15/42 36/15+15/21 12/15+45/21 12/45+15/21 12/15+15/63 60/15+15/21 12/15+75/21 12/75+15/21 84/15+15/21