To check if the student is correct, we are going to solve the equation step by step.
Step 1 divide both sides of the equation by 5:
\(5x^2=20\)
\(\frac{5x^2}{5} =\frac{20}{5}\)
\(x^2=4\)
Step 2 take square root to both sides of the equation:
\(\sqrt{x^2} =(+/-)\sqrt{4}\)
\(x=(+/-)\sqrt{4}\)
\(x=2\) or \(x=-2\)
The equation has tow solutions, \(x=2\) and \(x=-2\).
I disagree with the student because \(x=2\) is just one solution and not the only one; \(x=-2\) is also a valid solution of the equation.
