Answers

Add 12/42 and 12/21

12/42 + 12/21 is 6/7.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 42 and 21 is 42
   
   Next, find the equivalent fraction of both fractional numbers with denominator 42
2. For the 1st fraction, since 42 × 1 = 42,
   12/42 = 12 × 1/42 × 1 = 12/42
3. Likewise, for the 2nd fraction, since 21 × 2 = 42,
   12/21 = 12 × 2/21 × 2 = 24/42
4. Add the two like fractions:
   12/42 + 24/42 = 12 + 24/42 = 36/42
5. 36/42 simplified gives 6/7
6. So, 12/42 + 12/21 = 6/7

MathStep (Works offline)

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

Related: ²⁴/₄₂+¹²/₂₁ ¹²/₄₂+²⁴/₂₁ ¹²/₈₄+¹²/₂₁ ¹²/₄₂+¹²/₄₂ ³⁶/₄₂+¹²/₂₁ ¹²/₄₂+³⁶/₂₁ ¹²/₄₂+¹²/₆₃ ⁶⁰/₄₂+¹²/₂₁ ¹²/₄₂+⁶⁰/₂₁ ⁸⁴/₄₂+¹²/₂₁ ¹²/₄₂+⁸⁴/₂₁

Add Fractions Calculator