Add 15/21 and 20/15
1st number: 15/21, 2nd number: 1 5/15
15/21 + 20/15 is 43/21.
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,
15/21 = 15 × 5/21 × 5 = 75/105 - Likewise, for the 2nd fraction, since 15 × 7 = 105,
20/15 = 20 × 7/15 × 7 = 140/105 - Add the two like fractions:
75/105 + 140/105 = 75 + 140/105 = 215/105 - 215/105 simplified gives 43/21
- So, 15/21 + 20/15 = 43/21
In mixed form: 21/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/21+20/15 15/21+40/15 15/42+20/15 15/21+20/30 45/21+20/15 15/21+60/15 15/63+20/15 15/21+20/45 75/21+20/15 15/21+20/75