Add 56/15 and 20/21
1st number: 3 11/15, 2nd number: 20/21
56/15 + 20/21 is 164/35.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 21 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 15 × 7 = 105,
56/15 = 56 × 7/15 × 7 = 392/105 - Likewise, for the 2nd fraction, since 21 × 5 = 105,
20/21 = 20 × 5/21 × 5 = 100/105 - Add the two like fractions:
392/105 + 100/105 = 392 + 100/105 = 492/105 - 492/105 simplified gives 164/35
- So, 56/15 + 20/21 = 164/35
In mixed form: 424/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/15+40/21 56/30+20/21 56/15+20/42 56/15+60/21 56/45+20/21 56/15+20/63 56/75+20/21