Respuesta :

Answer: k = 12

Step-by-step explanation:

x² + kx + 36 = 0

In order for x to have exactly one solution, it must be a perfect square.

(x + √36)² = 0

(x + 6)² = 0

(x + 6)(x + 6) = 0

x² + 6x + 6x + 36 = 0

x² + 12x + 36 = 0

 k = 12