(4)

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The equations are $\"\"$ and $\"\"$ .

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Substitute $\"\"$ in $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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Substitute $\"\"$ in $\"\"$ .

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$\"\"$

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$\"\"$

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Therefore, the solutions are $\"\"$ and $\"\"$ .

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(5)

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The equations are $\"\"$ and $\"\"$ .

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Consider the equation $\"\"$ .

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Solve for $\"\"$ .

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$\"\"$ .

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Substitute $\"\"$ in $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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Substitute $\"\"$ in $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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Therefore, the solutions are $\"\"$ and $\"\"$ .

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(6)

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The equations are $\"\"$ and $\"\"$ .

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Consider the equation $\"\"$ .

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Solve for $\"\"$ .

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$\"\"$ .

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$\"\"$

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$\"\"$

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Substitute $\"\"$ in $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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$\"\"$

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Substitute $\"\"$ in $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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Therefore, the solutions are $\"\"$ and $\"\"$ .

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