Question

What are the solution(s) of x2-4-0?

Of
X=-4 or x = 4
O x=-2 or x = 2
Ox=2
O X=4
o

Answer 1

x = -2 or x = 2

Explanation:

`x^2-4=0\qquad\text{add 4 to both sides}\\\\x^2-4+4=0+4\\\\x^2=4\iff√(x^2)=\sqrt4\\\\|x|=2\Rightarrow x=\pm2`

Answer 2

For
`x^2 - 4 = 0`, x = 2, or x = - 2.

Explanation:

Here, the given expression is :

`x^2 - 4 = 0`

Now, using the ALGEBRAIC IDENTITY:

`a^2 - b^2 = (a-b)(a+b)`

Comparing this with the above expression, we get

`x^2 - 4 = 0  = x^2 - (2)^2 = 0\\\implies (x-2)(x+2) = 0`

⇒Either (x-2) = 0 , or ( x + 2) = 0

So, if ( x- 2) = 0 ⇒ x = 2

and if ( x + 2) = 0 ⇒ x = -2

Hence, for
`x^2 - 4 = 0`, x = 2, or x = - 2.