Add 30/21 and 9/72, Solve 1 9/21 + 9/72 as a fraction

Add 30/21 and 9/72

1^st number: 1 9/21, 2^nd number: 9/72

30/21 + 9/72 is 87/56.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 72 is 504

Next, find the equivalent fraction of both fractional numbers with denominator 504
For the 1st fraction, since 21 × 24 = 504,
30/21 = 30 × 24/21 × 24 = 720/504
Likewise, for the 2nd fraction, since 72 × 7 = 504,
9/72 = 9 × 7/72 × 7 = 63/504
Add the two like fractions:
720/504 + 63/504 = 720 + 63/504 = 783/504
783/504 simplified gives 87/56
So, 30/21 + 9/72 = 87/56
In mixed form: 131/56

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad