Question

applying the square root property of equality
a student says that if $5x^2 = 20$, then $x$ must be equal to 2. do you agree or disagree with the student? justify your answer.
done

Explanation:

Step1: Isolate $x^2$ term

Divide both sides by 5:
$\frac{5x^2}{5} = \frac{20}{5}$
$x^2 = 4$

Step2: Apply square root property

Take square root of both sides, account for both positive and negative roots:
$x = \pm\sqrt{4}$
$x = 2 \text{ or } x = -2$

Answer:

Disagree with the student. When solving $5x^2=20$, we find $x=2$ and $x=-2$, since squaring both positive and negative 2 gives 4, which satisfies the equation after substituting back. The student only identified one of the two valid solutions.