Add 72/9 and 3/21
1st number: 8 0/9, 2nd number: 3/21
72/9 + 3/21 is 57/7.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 9 and 21 is 63
Next, find the equivalent fraction of both fractional numbers with denominator 63 - For the 1st fraction, since 9 × 7 = 63,
72/9 = 72 × 7/9 × 7 = 504/63 - Likewise, for the 2nd fraction, since 21 × 3 = 63,
3/21 = 3 × 3/21 × 3 = 9/63 - Add the two like fractions:
504/63 + 9/63 = 504 + 9/63 = 513/63 - 513/63 simplified gives 57/7
- So, 72/9 + 3/21 = 57/7
In mixed form: 81/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/9+6/21 72/18+3/21 72/9+3/42 72/9+9/21 72/27+3/21 72/9+3/63 72/9+15/21 72/45+3/21 72/63+3/21