Add 72/42 and 20/40
1st number: 1 30/42, 2nd number: 20/40
72/42 + 20/40 is 31/14.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 42 × 20 = 840,
72/42 = 72 × 20/42 × 20 = 1440/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
20/40 = 20 × 21/40 × 21 = 420/840 - Add the two like fractions:
1440/840 + 420/840 = 1440 + 420/840 = 1860/840 - 1860/840 simplified gives 31/14
- So, 72/42 + 20/40 = 31/14
In mixed form: 23/14
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/84+20/40 72/42+20/80 72/42+60/40