Add 5/21 and 84/72, Solve 5/21 + 1 12/72 as a fraction

Add 5/21 and 84/72

1^st number: 5/21, 2^nd number: 1 12/72

5/21 + 84/72 is 59/42.

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,
5/21 = 5 × 24/21 × 24 = 120/504
Likewise, for the 2nd fraction, since 72 × 7 = 504,
84/72 = 84 × 7/72 × 7 = 588/504
Add the two like fractions:
120/504 + 588/504 = 120 + 588/504 = 708/504
708/504 simplified gives 59/42
So, 5/21 + 84/72 = 59/42
In mixed form: 117/42

MathStep (Works offline)

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