Add 45/42 and 20/72
1st number: 1 3/42, 2nd number: 20/72
45/42 + 20/72 is 85/63.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 72 is 504
Next, find the equivalent fraction of both fractional numbers with denominator 504 - For the 1st fraction, since 42 × 12 = 504,
45/42 = 45 × 12/42 × 12 = 540/504 - Likewise, for the 2nd fraction, since 72 × 7 = 504,
20/72 = 20 × 7/72 × 7 = 140/504 - Add the two like fractions:
540/504 + 140/504 = 540 + 140/504 = 680/504 - 680/504 simplified gives 85/63
- So, 45/42 + 20/72 = 85/63
In mixed form: 122/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/42+20/72 45/42+40/72 45/84+20/72 45/42+60/72