Question about properties and characteristics of functions

3.  Divide   f(x)  into the product   f *g    to find  g(x) 

 

4.   I'm not sure I understand this question      f*g  =  g*f       ??

                -3x (x^2/(2x-3))   =     -3x^3 / (2x-3)      x cannot equal 1  1/2     otherwise all  x   ??