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Subtract 21/18 from 7/15

1st number: 7/15, 2nd number: 1 3/18

7/15 - 21/18 is -7/10.

Steps for subtracting fractions

  1. Find the least common denominator or LCM of the two denominators:
    LCM of 15 and 18 is 90

    Next, find the equivalent fraction of both fractional numbers with denominator 90
  2. For the 1st fraction, since 15 × 6 = 90,
    7/15 = 7 × 6/15 × 6 = 42/90
  3. Likewise, for the 2nd fraction, since 18 × 5 = 90,
    21/18 = 21 × 5/18 × 5 = 105/90
  4. Subtract the two like fractions:
    42/90 - 105/90 = 42 - 105/90 = -63/90
  5. After reducing the fraction, the answer is -7/10

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