Question

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.

Explanation:

Step1: Isolate $x^2$ term

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

Step2: Solve for $x$

Take square root of both sides:
$x = \pm\sqrt{4}$
Simplify to get $x = 2$ or $x = -2$

Answer:

Disagree. The solutions to $5x^2=20$ are $x=2$ and $x=-2$, so $x$ does not have to be 2.