Add 20/84 and 72/20
1st number: 20/84, 2nd number: 3 12/20
20/84 + 72/20 is 403/105.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 84 × 5 = 420,
20/84 = 20 × 5/84 × 5 = 100/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
72/20 = 72 × 21/20 × 21 = 1512/420 - Add the two like fractions:
100/420 + 1512/420 = 100 + 1512/420 = 1612/420 - 1612/420 simplified gives 403/105
- So, 20/84 + 72/20 = 403/105
In mixed form: 388/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/84+72/20 20/84+72/40 60/84+72/20 20/84+72/60