Add 28/21 and 20/35
1st number: 1 7/21, 2nd number: 20/35
28/21 + 20/35 is 40/21.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 35 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 21 × 5 = 105,
28/21 = 28 × 5/21 × 5 = 140/105 - Likewise, for the 2nd fraction, since 35 × 3 = 105,
20/35 = 20 × 3/35 × 3 = 60/105 - Add the two like fractions:
140/105 + 60/105 = 140 + 60/105 = 200/105 - 200/105 simplified gives 40/21
- So, 28/21 + 20/35 = 40/21
In mixed form: 119/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/21+20/35 28/21+40/35 28/42+20/35 28/21+20/70 84/21+20/35 28/21+60/35 28/63+20/35