Answers

Add 81/20 and 75/42

1^st number: 4 1/20, 2^nd number: 1 33/42

81/20 + 75/42 is 817/140.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 20 and 42 is 420
   
   Next, find the equivalent fraction of both fractional numbers with denominator 420
2. For the 1st fraction, since 20 × 21 = 420,
   81/20 = 81 × 21/20 × 21 = 1701/420
3. Likewise, for the 2nd fraction, since 42 × 10 = 420,
   75/42 = 75 × 10/42 × 10 = 750/420
4. Add the two like fractions:
   1701/420 + 750/420 = 1701 + 750/420 = 2451/420
5. 2451/420 simplified gives 817/140
6. So, 81/20 + 75/42 = 817/140
   In mixed form: 5117/140

MathStep (Works offline)

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

Related: ⁸¹/₄₀+⁷⁵/₄₂ ⁸¹/₂₀+⁷⁵/₈₄ ⁸¹/₆₀+⁷⁵/₄₂

Add Fractions Calculator