Add 42/80 and 64/90
42/80 + 64/90 is 89/72.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 90 is 720
Next, find the equivalent fraction of both fractional numbers with denominator 720 - For the 1st fraction, since 80 × 9 = 720,
42/80 = 42 × 9/80 × 9 = 378/720 - Likewise, for the 2nd fraction, since 90 × 8 = 720,
64/90 = 64 × 8/90 × 8 = 512/720 - Add the two like fractions:
378/720 + 512/720 = 378 + 512/720 = 890/720 - 890/720 simplified gives 89/72
- So, 42/80 + 64/90 = 89/72
In mixed form: 117/72
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/80+64/90