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Add 21/42 and 81/90

21/42 + 81/90 is 7/5.

Steps for adding fractions

  1. Find the least common denominator or LCM of the two denominators:
    LCM of 42 and 90 is 630

    Next, find the equivalent fraction of both fractional numbers with denominator 630
  2. For the 1st fraction, since 42 × 15 = 630,
    21/42 = 21 × 15/42 × 15 = 315/630
  3. Likewise, for the 2nd fraction, since 90 × 7 = 630,
    81/90 = 81 × 7/90 × 7 = 567/630
  4. Add the two like fractions:
    315/630 + 567/630 = 315 + 567/630 = 882/630
  5. 882/630 simplified gives 7/5
  6. So, 21/42 + 81/90 = 7/5
    In mixed form: 12/5

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