Final answer:
The function f(x)=3|3x+1|-6 cannot be simplified further without additional information about the value of x. None of the provided answer choices are correct simplifications of the function f(x).
Step-by-step explanation:
The question asks to solve the function f(x)=3|3x+1|-6. We cannot simplify this further without knowing the value of x because the absolute value function will affect the calculation depending on whether 3x+1 is positive or negative. None of the provided options (a) f(x)=9x+3, (b) f(x)=-9x+3, (c) f(x)=9|3x+1|-6, or (d) f(x)=-9|3x+1|-6 represent the simplification of f(x) as they change the overall structure of the function or neglect the fact that there is an absolute value involved which needs consideration. Therefore, none of the options provided correctly represent the function f(x).