Add 21/80 and 42/54
21/80 + 42/54 is 749/720.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 54 is 2160
Next, find the equivalent fraction of both fractional numbers with denominator 2160 - For the 1st fraction, since 80 × 27 = 2160,
21/80 = 21 × 27/80 × 27 = 567/2160 - Likewise, for the 2nd fraction, since 54 × 40 = 2160,
42/54 = 42 × 40/54 × 40 = 1680/2160 - Add the two like fractions:
567/2160 + 1680/2160 = 567 + 1680/2160 = 2247/2160 - 2247/2160 simplified gives 749/720
- So, 21/80 + 42/54 = 749/720
In mixed form: 129/720
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/80+42/54 21/80+84/54 63/80+42/54