Answer
False. For example, $\lfloor(-1.5)^{2}\rfloor=\lfloor2.25\rfloor=2$, but $\lfloor-1.5\rfloor^{2}=(-2)^{2}=4$.
Work Step by Step
Remember to systematically search for counterexamples. For example, try $x$ positive and $x$ negative, $x$ integer and $x$ non-integer, and so on.
