To simplify the expression \((−7−\sqrt{−100})−(−15−\sqrt{−81})\), let's break it down step by step.
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First, handle the square roots of the negative numbers:
- \(\sqrt{-100} = \sqrt{100} \cdot \sqrt{-1} = 10i\)
- \(\sqrt{-81} = \sqrt{81} \cdot \sqrt{-1} = 9i\)
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Replace the square roots in the expression: \[ (−7−10i)−(−15−9i) \]
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Distributing the negative sign in front of the second parenthesis: \[ −7−10i + 15 + 9i \]
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Combine like terms:
- For the real parts: \(-7 + 15 = 8\)
- For the imaginary parts: \(-10i + 9i = -i\)
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Therefore, the expression simplifies to: \[ 8 - i \]
Thus, the simplified expression is \(8 - i\).
The correct option is: 8−i (8 minus i).