Add 30/21 and 72/20
1st number: 1 9/21, 2nd number: 3 12/20
30/21 + 72/20 is 176/35.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 21 × 20 = 420,
30/21 = 30 × 20/21 × 20 = 600/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
72/20 = 72 × 21/20 × 21 = 1512/420 - Add the two like fractions:
600/420 + 1512/420 = 600 + 1512/420 = 2112/420 - 2112/420 simplified gives 176/35
- So, 30/21 + 72/20 = 176/35
In mixed form: 51/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/21+72/20 30/42+72/20 30/21+72/40 90/21+72/20 30/63+72/20 30/21+72/60