Answers

Add 81/28 and 42/90

1^st number: 2 25/28, 2^nd number: 42/90

81/28 + 42/90 is 1411/420.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 28 and 90 is 1260
   
   Next, find the equivalent fraction of both fractional numbers with denominator 1260
2. For the 1st fraction, since 28 × 45 = 1260,
   81/28 = 81 × 45/28 × 45 = 3645/1260
3. Likewise, for the 2nd fraction, since 90 × 14 = 1260,
   42/90 = 42 × 14/90 × 14 = 588/1260
4. Add the two like fractions:
   3645/1260 + 588/1260 = 3645 + 588/1260 = 4233/1260
5. 4233/1260 simplified gives 1411/420
6. So, 81/28 + 42/90 = 1411/420
   In mixed form: 3151/420

MathStep (Works offline)

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

Related: ⁸¹/₂₈+⁸⁴/₉₀ ⁸¹/₅₆+⁴²/₉₀ ⁸¹/₈₄+⁴²/₉₀

Add Fractions Calculator