Add 72/42 and 21/30
1st number: 1 30/42, 2nd number: 21/30
72/42 + 21/30 is 169/70.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 30 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 42 × 5 = 210,
72/42 = 72 × 5/42 × 5 = 360/210 - Likewise, for the 2nd fraction, since 30 × 7 = 210,
21/30 = 21 × 7/30 × 7 = 147/210 - Add the two like fractions:
360/210 + 147/210 = 360 + 147/210 = 507/210 - 507/210 simplified gives 169/70
- So, 72/42 + 21/30 = 169/70
In mixed form: 229/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/42+42/30 72/84+21/30 72/42+21/60 72/42+63/30 72/42+21/90