Hello, mm99!
Can someone explain how to do sign graphs for inequalities?
Like: .$\displaystyle (x3)(x+4)\:>\:0$ Here's one way . . .
We have the graph of: .$\displaystyle y \:=\:(x3)(x+4)\quad\Rightarrow\quad y \:=\:x^2+x12$
This is an upopening parabola.
We want to know when this graph is positive (above the xaxis).
Draw a sketch (or visualize it) . . .
The xintercepts are $\displaystyle x = 4,\:3$
The graph is positive to the left and right of the intercepts. Code:

*  *

*  *
*  *
  *       +     *  
4 *  * 3
*  *
* 

Therefore: .$\displaystyle (\infty,\:4) \cup (3,\:\infty)$