Respuesta :

Answer:

x^2 -10x - 15 = 0

(don't know how far you want me to go)

Step-by-step explanation:

(x - 5)^2 = 40

(expand the brackets)

(x - 5)(x - 5) = 40

x^2 -5x -5x + 25 = 40

x^2 -10x + 25 = 40

x^2 -10x - 15 = 0