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Add 3/20 and 9/21

3/20 + 9/21 is 81/140.

Steps for adding fractions

  1. Find the least common denominator or LCM of the two denominators:
    LCM of 20 and 21 is 420

    Next, find the equivalent fraction of both fractional numbers with denominator 420
  2. For the 1st fraction, since 20 × 21 = 420,
    3/20 = 3 × 21/20 × 21 = 63/420
  3. Likewise, for the 2nd fraction, since 21 × 20 = 420,
    9/21 = 9 × 20/21 × 20 = 180/420
  4. Add the two like fractions:
    63/420 + 180/420 = 63 + 180/420 = 243/420
  5. 243/420 simplified gives 81/140
  6. So, 3/20 + 9/21 = 81/140

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