Respuesta :

Answer:

For [tex]x^2 - 4 = 0[/tex], x  = 2, or x = - 2.

Step-by-step explanation:

Here, the given expression is :

[tex]x^2 - 4 = 0[/tex]

Now, using the ALGEBRAIC IDENTITY:

[tex]a^2 - b^2 = (a-b)(a+b)[/tex]

Comparing this with the above expression, we get

[tex]x^2 - 4 = 0  = x^2 - (2)^2 = 0\\\implies (x-2)(x+2) = 0[/tex]

⇒Either (x-2) = 0 , or ( x + 2) = 0

So, if ( x- 2)   = 0 ⇒ x =  2

and if ( x + 2) = 0   ⇒ x = -2

Hence, for [tex]x^2 - 4 = 0[/tex], x  = 2, or x = - 2.

gmany

Answer:

x = -2 or x = 2

Step-by-step explanation:

[tex]x^2-4=0\qquad\text{add 4 to both sides}\\\\x^2-4+4=0+4\\\\x^2=4\iff\sqrt{x^2}=\sqrt4\\\\|x|=2\Rightarrow x=\pm2[/tex]

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