What are the solutions of the equation open paren x minus 3 close paren squared plus 2 times open paren x minus 3 close paren minus 8 is equal to 0 ? Use u substitution to solve.

Let u = x − 3. The equation becomes u² + 2u − 8 = 0, which factors as (u + 4)(u − 2) = 0, so u = −4 or u = 2. Since x − 3 = u, these give x = −1 or x = 5. The correct choice is C, x = −1 and x = 5.

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