Add 15/21 and 1/7
15/21 + 1/7 is 6/7.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 7 is 21
Next, find the equivalent fraction of both fractional numbers with denominator 21 - For the 1st fraction, since 21 × 1 = 21,
15/21 = 15 × 1/21 × 1 = 15/21 - Likewise, for the 2nd fraction, since 7 × 3 = 21,
1/7 = 1 × 3/7 × 3 = 3/21 - Add the two like fractions:
15/21 + 3/21 = 15 + 3/21 = 18/21 - 18/21 simplified gives 6/7
- So, 15/21 + 1/7 = 6/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/21+1/7 15/21+2/7 15/42+1/7 15/21+1/14 45/21+1/7 15/21+3/7 15/63+1/7 15/21+1/21 75/21+1/7 15/21+5/7 15/21+1/35 15/21+1/49