Add 72/90 and 12/20
72/90 + 12/20 is 7/5.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 20 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 90 × 2 = 180,
72/90 = 72 × 2/90 × 2 = 144/180 - Likewise, for the 2nd fraction, since 20 × 9 = 180,
12/20 = 12 × 9/20 × 9 = 108/180 - Add the two like fractions:
144/180 + 108/180 = 144 + 108/180 = 252/180 - 252/180 simplified gives 7/5
- So, 72/90 + 12/20 = 7/5
In mixed form: 12/5
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/90+24/20 72/90+12/40 72/90+36/20 72/90+12/60 72/90+60/20 72/90+84/20