$A$ is an $n\times n$ matrix, $n \ge 3$. Assume $A^2 = 0$. Which one is true and which one is false and explain:
The linear system $Ax = 0$ has only trivial solution.
The linear system $Ax = 0$ has more than only the trivial solution.
The linear system $(I - A)x$ has only trivial solution.