Add 72/81 and 20/15
1st number: 72/81, 2nd number: 1 5/15
72/81 + 20/15 is 20/9.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 15 is 405
Next, find the equivalent fraction of both fractional numbers with denominator 405 - For the 1st fraction, since 81 × 5 = 405,
72/81 = 72 × 5/81 × 5 = 360/405 - Likewise, for the 2nd fraction, since 15 × 27 = 405,
20/15 = 20 × 27/15 × 27 = 540/405 - Add the two like fractions:
360/405 + 540/405 = 360 + 540/405 = 900/405 - 900/405 simplified gives 20/9
- So, 72/81 + 20/15 = 20/9
In mixed form: 22/9
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/81+40/15 72/81+20/30 72/81+60/15 72/81+20/45 72/81+20/75