Answers

Add 42/21 and 28/90

1^st number: 2 0/21, 2^nd number: 28/90

42/21 + 28/90 is 104/45.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 21 and 90 is 630
   
   Next, find the equivalent fraction of both fractional numbers with denominator 630
2. For the 1st fraction, since 21 × 30 = 630,
   42/21 = 42 × 30/21 × 30 = 1260/630
3. Likewise, for the 2nd fraction, since 90 × 7 = 630,
   28/90 = 28 × 7/90 × 7 = 196/630
4. Add the two like fractions:
   1260/630 + 196/630 = 1260 + 196/630 = 1456/630
5. 1456/630 simplified gives 104/45
6. So, 42/21 + 28/90 = 104/45
   In mixed form: 214/45

MathStep (Works offline)

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

Related: ⁸⁴/₂₁+²⁸/₉₀ ⁴²/₂₁+⁵⁶/₉₀ ⁴²/₂₁+⁸⁴/₉₀ ⁴²/₆₃+²⁸/₉₀

Add Fractions Calculator