1. The problem is to simplify the expression $[3X] - 3$. 2. Here, $[3X]$ denotes the greatest integer function (floor function) applied to $3X$, which means it is the greatest integer less than or equal to $3X$. 3. The expression $[3X] - 3$ means we take the floor of $3X$ and then subtract 3 from it. 4. There is no further simplification possible without knowing the value of $X$. 5. So the simplified form remains $[3X] - 3$. 6. If you want to express it in terms of $X$, it is simply the floor of $3X$ minus 3.