Can you please help me by telling me which one is the answer and how do I solve to get the answer. 
Thank you 
                                             
                                          
                                          
                                        
											 
											( 3x - 12 / 9x^2 ) ÷ ( x - 4 / 3x ) =
( 3x - 12 / 9x^2 ) × ( 3x / x - 4 ) =
( 3 ( x - 4 ) / 3 × 3x × x ) × ( 3x / x - 4 ) =
( x - 4 / 3x × x ) × ( 3x / x - 4 ) =
( x - 4 ) × 3x / ( x - 4 ) × 3x × x =
1 / x
Thus the correct answer is option A .