Add 70/20 and 21/72
1st number: 3 10/20, 2nd number: 21/72
70/20 + 21/72 is 91/24.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 72 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 20 × 18 = 360,
70/20 = 70 × 18/20 × 18 = 1260/360 - Likewise, for the 2nd fraction, since 72 × 5 = 360,
21/72 = 21 × 5/72 × 5 = 105/360 - Add the two like fractions:
1260/360 + 105/360 = 1260 + 105/360 = 1365/360 - 1365/360 simplified gives 91/24
- So, 70/20 + 21/72 = 91/24
In mixed form: 319/24
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 70/20+42/72 70/40+21/72 70/20+63/72 70/60+21/72