Add 28/35 and 21/81
28/35 + 21/81 is 143/135.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 35 and 81 is 2835
Next, find the equivalent fraction of both fractional numbers with denominator 2835 - For the 1st fraction, since 35 × 81 = 2835,
28/35 = 28 × 81/35 × 81 = 2268/2835 - Likewise, for the 2nd fraction, since 81 × 35 = 2835,
21/81 = 21 × 35/81 × 35 = 735/2835 - Add the two like fractions:
2268/2835 + 735/2835 = 2268 + 735/2835 = 3003/2835 - 3003/2835 simplified gives 143/135
- So, 28/35 + 21/81 = 143/135
In mixed form: 18/135
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/35+21/81 28/35+42/81 28/70+21/81 84/35+21/81 28/35+63/81