Add 20/28 and 42/90
20/28 + 42/90 is 124/105.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 90 is 1260
Next, find the equivalent fraction of both fractional numbers with denominator 1260 - For the 1st fraction, since 28 × 45 = 1260,
20/28 = 20 × 45/28 × 45 = 900/1260 - Likewise, for the 2nd fraction, since 90 × 14 = 1260,
42/90 = 42 × 14/90 × 14 = 588/1260 - Add the two like fractions:
900/1260 + 588/1260 = 900 + 588/1260 = 1488/1260 - 1488/1260 simplified gives 124/105
- So, 20/28 + 42/90 = 124/105
In mixed form: 119/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/28+42/90 20/28+84/90 20/56+42/90 60/28+42/90 20/84+42/90