I'm not quite sure what you mean....
If I could hazard a guess, you're pretty much asking when> 0
Well (1-x)^4 is always positive. So, the sign of the polynomial is dependent upon (3-2x)(x+3). If you draw the graph (3-2x)(x+3), you'll find it is negative when x<-3, or x> 3/2, and it is positive -3<x<3/2
I look at the largest root which in this case is 3/2. You then sub an easy number greater than that like 2 and see if the result is positive or negative.