What is the polynomial 3y2 + (y + 7)2 – 15 after it has been fully simplified and written in standard form?

First expand the square: (y + 7)² = y² + 14y + 49. Add 3y² and subtract 15: 3y² + y² + 14y + 49 − 15 = 4y² + 14y + 34. This is choice C, 4y² + 14y + 34.

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