Answer
The square of negative $x$ is not equal to the negative of the square of $x$.
We know that $(-x)^2=(-x)\cdot(-x)$.
Since the product of even number of the negative numbers is positive.
We get, $(-x)^2=x^2$
Hence, $(-x)^2$ is not equivalent to $-x^2$.
Work Step by Step
The square of negative $x$ is not equal to the negative of the square of $x$.
We know that $(-x)^2=(-x)\cdot(-x)$.
Since the product of even number of the negative numbers is positive.
We get, $(-x)^2=x^2$
Hence, $(-x)^2$ is not equivalent to $-x^2$.