Answer:
-3x
Explanation:
This just goes down to very little rules. X's (even though not seen) always has an invisible number behind it (1). X is by itself, so is one of itself. We dont put the number there as it is just extra work, but it is there. When you have -X, you have minus one of that X, so you have -1x. The question is kinda weird stated, but I believe it is -3x. If you were to plug in -1x as x (x=-1x) then the answer would be -3x^2. So up to how the question is stated.