Add 15/14 and 21/12, Solve 1 1/14 + 1 9/12 as a fraction

Add 15/14 and 21/12

1^st number: 1 1/14, 2^nd number: 1 9/12

15/14 + 21/12 is 79/28.

Find the least common denominator or LCM of the two denominators:
LCM of 14 and 12 is 84

Next, find the equivalent fraction of both fractional numbers with denominator 84
For the 1st fraction, since 14 × 6 = 84,
15/14 = 15 × 6/14 × 6 = 90/84
Likewise, for the 2nd fraction, since 12 × 7 = 84,
21/12 = 21 × 7/12 × 7 = 147/84
Add the two like fractions:
90/84 + 147/84 = 90 + 147/84 = 237/84
237/84 simplified gives 79/28
So, 15/14 + 21/12 = 79/28
In mixed form: 223/28

MathStep (Works offline)

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