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Add 15/21 and 35/40

15/21 + 35/40 is 89/56.

Steps for adding fractions

  1. Find the least common denominator or LCM of the two denominators:
    LCM of 21 and 40 is 840
  2. For the 1st fraction, since 21 × 40 = 840,
    15/21 = 15 × 40/21 × 40 = 600/840
  3. Likewise, for the 2nd fraction, since 40 × 21 = 840,
    35/40 = 35 × 21/40 × 21 = 735/840
  4. Add the two fractions:
    600/840 + 735/840 = 600 + 735/840 = 1335/840
  5. 1335/840 simplified gives 89/56
  6. So, 15/21 + 35/40 = 89/56
    In mixed form: 133/56

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