Add 40/72 and 42/80
40/72 + 42/80 is 389/360.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 80 is 720
Next, find the equivalent fraction of both fractional numbers with denominator 720 - For the 1st fraction, since 72 × 10 = 720,
40/72 = 40 × 10/72 × 10 = 400/720 - Likewise, for the 2nd fraction, since 80 × 9 = 720,
42/80 = 42 × 9/80 × 9 = 378/720 - Add the two like fractions:
400/720 + 378/720 = 400 + 378/720 = 778/720 - 778/720 simplified gives 389/360
- So, 40/72 + 42/80 = 389/360
In mixed form: 129/360
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/72+42/80 40/72+84/80