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Add 21/12 and 27/15

1st number: 1 9/12, 2nd number: 1 12/15

21/12 + 27/15 is 71/20.

Steps for adding fractions

  1. Find the least common denominator or LCM of the two denominators:
    LCM of 12 and 15 is 60

    Next, find the equivalent fraction of both fractional numbers with denominator 60
  2. For the 1st fraction, since 12 × 5 = 60,
    21/12 = 21 × 5/12 × 5 = 105/60
  3. Likewise, for the 2nd fraction, since 15 × 4 = 60,
    27/15 = 27 × 4/15 × 4 = 108/60
  4. Add the two like fractions:
    105/60 + 108/60 = 105 + 108/60 = 213/60
  5. 213/60 simplified gives 71/20
  6. So, 21/12 + 27/15 = 71/20
    In mixed form: 311/20

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