Question 7723
 You posted this question in wrong category.
 
 To solve f(x) = x(x + 3)(x – 1) >0
 The three roots of f(x) = 0 are -3,0 and 1 (in this order)

 Consider the signs of the diagram below:
    --         +++     --    ++++
  ----------*---------*---*-------------
            -3        0   1  
 So, the  solution of f(x)>0 is 
  (-3,0) U (1,+oo)

 Kenny

 PS: You have to redraw the diagram on your own paper.