Add 9/7 and 21/81, Solve 1 2/7 + 21/81 as a fraction

Add 9/7 and 21/81

1^st number: 1 2/7, 2^nd number: 21/81

9/7 + 21/81 is 292/189.

Find the least common denominator or LCM of the two denominators:
LCM of 7 and 81 is 567

Next, find the equivalent fraction of both fractional numbers with denominator 567
For the 1st fraction, since 7 × 81 = 567,
9/7 = 9 × 81/7 × 81 = 729/567
Likewise, for the 2nd fraction, since 81 × 7 = 567,
21/81 = 21 × 7/81 × 7 = 147/567
Add the two like fractions:
729/567 + 147/567 = 729 + 147/567 = 876/567
876/567 simplified gives 292/189
So, 9/7 + 21/81 = 292/189
In mixed form: 1103/189

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad