Which equation is y is equal to open paren x plus 3 close paren squared plus open paren x plus 4 close paren squared rewritten in vertex form?

Expand the expression: (x + 3)² + (x + 4)² = 2x² + 14x + 25. The vertex has x-coordinate −14 ÷ (2 · 2) = −7/2; substituting this value gives y = 1/2. Thus the vertex form is y = 2(x + 7/2)² + 1/2, which is choice B.

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