Add 72/21 and 84/80
1st number: 3 9/21, 2nd number: 1 4/80
72/21 + 84/80 is 627/140.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 80 is 1680
Next, find the equivalent fraction of both fractional numbers with denominator 1680 - For the 1st fraction, since 21 × 80 = 1680,
72/21 = 72 × 80/21 × 80 = 5760/1680 - Likewise, for the 2nd fraction, since 80 × 21 = 1680,
84/80 = 84 × 21/80 × 21 = 1764/1680 - Add the two like fractions:
5760/1680 + 1764/1680 = 5760 + 1764/1680 = 7524/1680 - 7524/1680 simplified gives 627/140
- So, 72/21 + 84/80 = 627/140
In mixed form: 467/140
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/42+84/80 72/63+84/80