Respuesta :

If x² = 100, then x = 10  →  NOT true

Because 
If x² = 100, then x = ±10

Answer:

Statement represented by option B is not a correct choice.

Step-by-step explanation:

We have been given 4 statements. We are asked to choose the statement that is not true.

A. [tex]x^2=100[/tex], if and only if [tex]x=10\text{ or }x=-10[/tex].

Let us solve for x by taking square root of both sides of our given equation.

[tex]\sqrt{x^2}=\sqrt{100}[/tex]

[tex]\sqrt{x^2}=\sqrt{10^2}[/tex]

[tex]x=\pm 10[/tex]

[tex]x=10\text{ or }x=-10[/tex]

Therefore, our given statement is true.

B. [tex]x^2=100[/tex], then [tex]x=10[/tex].

Upon taking square root we will get positive and negative 10, therefore, the given statement is false.

C. If [tex]x=-10[/tex], then  [tex]x^2=100[/tex]

Since we know that square of a negative number is positive, therefore, square of negative 10 is 100 and the given statement is true.

D. If [tex]x=10[/tex], then  [tex]x^2=100[/tex]

Upon squaring 10 we will get 100, therefore, the given statement is true as well.