Respuesta :

flossyraven
x in (-oo:+oo)

(x+20)/2 = 3*x // - 3*x

(x+20)/2-(3*x) = 0

(x+20)/2-3*x = 0

(x+20)/2+(-3*2*x)/2 = 0

x-3*2*x+20 = 0

20-5*x = 0

(20-5*x)/2 = 0

(20-5*x)/2 = 0 // * 2

20-5*x = 0

20-5*x = 0 // - 20

-5*x = -20 // : -5

x = -20/(-5)

x = 4 so x= 4