Question

(x+2).(x-6)=0   obter as raizes reais das seguintes equaçoes

Answer 1

(x+2).(x-6)
x^2-6x+2x-12
x^2-4x-12=0
delta=b^2-4ac
delta=(-4)^2-4.1.(-12)
delta=16+48
delta=64
x=-b-/+ raiz de delta/2a
x=-(-4)-8/2.1
x=4-8/2
x=-4/2
x=-2
x=-(-4)+8/2.1
x=4+8/2
x=12/2
x=6
S={-2, 6}