Which equation is y is equal to 2 x squared minus 8 x plus 9 rewritten in vertex form?

Factor 2 from the quadratic and linear terms: y = 2(x² − 4x) + 9. Completing the square gives x² − 4x = (x − 2)² − 4, so y = 2(x − 2)² − 8 + 9 = 2(x − 2)² + 1. This is choice D.

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