Respuesta :

[tex] x^{2} - 25 = 0 \\ x^{2} = 0 + 25 \\ x^{2} = 25 \\ x = \pm \sqrt{25} \\ \boxed{x = \pm 5}[/tex]

correct alternatives : C , D
AL2006
x² - 25 = 0

The left side is the difference of 2 squares,
so we know right away, without any uncertainty
or sweat, that it can be written as

                   (x + 5) (x - 5) ,

and we know that it's equal to zero when either factor is zero.

Now let's look at the choices:

A.  X = -1  Not a chance.

B.  X = -3  Also no.

C.  X = -5  Yes that's good; that would make the first factor zero.

D.  X = 5    Yes that's good too; it would make the second factor zero.

E.  X = 3    Not true.  Don't know how they came up with it.

F.  X = 1    Equally not true.

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