Answer
$x^2\lt0$ has no solution and $x^2\leq0$ has $1$ solution.
Work Step by Step
We know that $x^2\geq0$ because the square of a real number is non-negative.
Hence $x^2\lt0$ has no solution (because $x^2$ is non-negative) and $x^2\leq0$ has $1$ solution (because $x^2$ is non-negative) and hence the only solution is for $x^2=0$ at $x=0$.
