The only solution of the equation x squared plus b x plus 16 is equal to 0 is x is equal to 4 What is the value of b ?

If 4 is the only solution, it must be a repeated root, so the quadratic can be written as (x − 4)² = 0. Expanding gives x² − 8x + 16 = 0, so the coefficient b is −8. Therefore, the correct choice is D, b is equal to negative 8.

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