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Decide whether the expression described ...

Decide whether the expression described is Positive, Negative, or Cannot Be Determined. If you answer Cannot Be Determined, give numerical examples to show how the problem could be either positive or negative.
`(-x)/((-y)(-z))`, given that `xyz gt0`

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To determine whether the expression \((-x)/((-y)(-z))\) is positive, negative, or cannot be determined given that \(xyz > 0\), we can follow these steps: ### Step 1: Analyze the given condition We know that \(xyz > 0\). This means that the product of \(x\), \(y\), and \(z\) is positive. This can occur in two scenarios: 1. All three variables \(x\), \(y\), and \(z\) are positive. 2. One variable is negative, and the other two are negative (since the product of two negative numbers is positive). ### Step 2: Rewrite the expression The expression can be rewritten as: \[ \frac{-x}{(-y)(-z)} = \frac{-x}{yz} \] This is because multiplying two negative numbers results in a positive number. ### Step 3: Determine the sign of the expression Now, we need to analyze the sign of \(-x\) and \(yz\): - The term \(yz\) is positive since \(xyz > 0\) and \(x\) is either positive or negative. - The term \(-x\) will be negative if \(x\) is positive, and it will be positive if \(x\) is negative. ### Step 4: Consider the cases for \(x\) 1. **Case 1:** If \(x > 0\) (meaning \(y\) and \(z\) must also be positive to keep \(xyz > 0\)): - Then, \(-x < 0\) and \(yz > 0\). - Therefore, \(\frac{-x}{yz} < 0\) (the expression is negative). 2. **Case 2:** If \(x < 0\) (meaning \(y\) and \(z\) must both be negative to keep \(xyz > 0\)): - Then, \(-x > 0\) and \(yz > 0\). - Therefore, \(\frac{-x}{yz} > 0\) (the expression is positive). ### Conclusion Based on the analysis: - If \(x > 0\), the expression is negative. - If \(x < 0\), the expression is positive. Thus, the expression \((-x)/((-y)(-z))\) cannot be determined without knowing the sign of \(x\). ### Numerical Examples To illustrate the conclusion: - **Example 1 (Negative Expression):** Let \(x = 1\), \(y = 2\), \(z = 3\). Then \(xyz = 1 \cdot 2 \cdot 3 = 6 > 0\) and \(\frac{-1}{(-2)(-3)} = \frac{-1}{6} < 0\). - **Example 2 (Positive Expression):** Let \(x = -1\), \(y = -2\), \(z = 3\). Then \(xyz = -1 \cdot -2 \cdot 3 = 6 > 0\) and \(\frac{-(-1)}{(-(-2))(-3)} = \frac{1}{6} > 0\). ### Final Answer The expression \((-x)/((-y)(-z))\) is **Cannot Be Determined**.
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