We solve for m in the middle.

We begin by adding 7 to all three sides:

 4 > -3m - 7 > 2
+7       + 7  +7 
----------------
11 > -3m     > 9

Then we divide all three sides by -3.  But when (but only when) 
we divide through by a negatve number, we reverse the inequalities:


  <  < 

   < m < -3

The graph would be:

------⚪=====⚫-----
         -3     

And the interval notation for that is:

      (, -3] 

Edwin