Answers

Add 54/21 and 30/40

1^st number: 2 12/21, 2^nd number: 30/40

54/21 + 30/40 is 93/28.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 21 and 40 is 840
   
   Next, find the equivalent fraction of both fractional numbers with denominator 840
2. For the 1st fraction, since 21 × 40 = 840,
   54/21 = 54 × 40/21 × 40 = 2160/840
3. Likewise, for the 2nd fraction, since 40 × 21 = 840,
   30/40 = 30 × 21/40 × 21 = 630/840
4. Add the two like fractions:
   2160/840 + 630/840 = 2160 + 630/840 = 2790/840
5. 2790/840 simplified gives 93/28
6. So, 54/21 + 30/40 = 93/28
   In mixed form: 39/28

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