Respuesta :

x^2 -5x -20=0
(x - 5/2)^2 -20 -25/4=0
(x-5/2)^2-105/4=0
(x -5/2 -(105)^1/2)(x -5/2 +(105)^1/2)=0
factors are (x -5/2 -(105)^1/2) and
(x -5/2 -(105)^1/2)