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Subtract 21/80 from 28/21

1st number: 1 7/21, 2nd number: 21/80

28/21 - 21/80 is 257/240.

Steps for subtracting fractions

  1. Find the least common denominator or LCM of the two denominators:
    LCM of 21 and 80 is 1680
  2. For the 1st fraction, since 21 × 80 = 1680,
    28/21 = 28 × 80/21 × 80 = 2240/1680
  3. Likewise, for the 2nd fraction, since 80 × 21 = 1680,
    21/80 = 21 × 21/80 × 21 = 441/1680
  4. Subtract the two fractions:
    2240/1680 - 441/1680 = 2240 - 441/1680 = 1799/1680
  5. After reducing the fraction, the answer is 257/240
  6. In mixed form: 117/240

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