Add 20/80 and 70/72
20/80 + 70/72 is 11/9.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 72 is 720
Next, find the equivalent fraction of both fractional numbers with denominator 720 - For the 1st fraction, since 80 × 9 = 720,
20/80 = 20 × 9/80 × 9 = 180/720 - Likewise, for the 2nd fraction, since 72 × 10 = 720,
70/72 = 70 × 10/72 × 10 = 700/720 - Add the two like fractions:
180/720 + 700/720 = 180 + 700/720 = 880/720 - 880/720 simplified gives 11/9
- So, 20/80 + 70/72 = 11/9
In mixed form: 12/9
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/80+70/72 60/80+70/72