Add 20/72 and 80/90
20/72 + 80/90 is 7/6.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 90 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 72 × 5 = 360,
20/72 = 20 × 5/72 × 5 = 100/360 - Likewise, for the 2nd fraction, since 90 × 4 = 360,
80/90 = 80 × 4/90 × 4 = 320/360 - Add the two like fractions:
100/360 + 320/360 = 100 + 320/360 = 420/360 - 420/360 simplified gives 7/6
- So, 20/72 + 80/90 = 7/6
In mixed form: 11/6
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/72+80/90 60/72+80/90