Add 90/28 and 21/72
1st number: 3 6/28, 2nd number: 21/72
90/28 + 21/72 is 589/168.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 72 is 504
Next, find the equivalent fraction of both fractional numbers with denominator 504 - For the 1st fraction, since 28 × 18 = 504,
90/28 = 90 × 18/28 × 18 = 1620/504 - Likewise, for the 2nd fraction, since 72 × 7 = 504,
21/72 = 21 × 7/72 × 7 = 147/504 - Add the two like fractions:
1620/504 + 147/504 = 1620 + 147/504 = 1767/504 - 1767/504 simplified gives 589/168
- So, 90/28 + 21/72 = 589/168
In mixed form: 385/168
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/28+42/72 90/56+21/72 90/28+63/72 90/84+21/72