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Example

Simplifying 9(15)9 - (-15) and 7(4)-7 - (-4) by Adding the Opposite

These paired computations confirm that subtracting a negative integer always produces the same result as adding the corresponding positive number:

  • 9(15)=249 - (-15) = 24 and 9+15=249 + 15 = 24: Both expressions evaluate to 2424, verifying that 9(15)=9+159 - (-15) = 9 + 15.
  • 7(4)=3-7 - (-4) = -3 and 7+4=3-7 + 4 = -3: Both expressions evaluate to 3-3, verifying that 7(4)=7+4-7 - (-4) = -7 + 4. In each pair, replacing the subtraction with addition of the opposite yields an identical answer. The pattern holds regardless of whether the starting number is positive or negative, reinforcing the general rule a(b)=a+ba - (-b) = a + b.

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Updated 2026-04-21

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