Answers

Add 21/84 and 20/56

21/84 + 20/56 is 17/28.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 84 and 56 is 168
   
   Next, find the equivalent fraction of both fractional numbers with denominator 168
2. For the 1st fraction, since 84 × 2 = 168,
   21/84 = 21 × 2/84 × 2 = 42/168
3. Likewise, for the 2nd fraction, since 56 × 3 = 168,
   20/56 = 20 × 3/56 × 3 = 60/168
4. Add the two like fractions:
   42/168 + 60/168 = 42 + 60/168 = 102/168
5. 102/168 simplified gives 17/28
6. So, 21/84 + 20/56 = 17/28

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad

Related: ⁴²/₈₄+²⁰/₅₆ ²¹/₈₄+⁴⁰/₅₆ ⁶³/₈₄+²⁰/₅₆ ²¹/₈₄+⁶⁰/₅₆

Add Fractions Calculator