-2x + 4 > 12

Subtract 4 from both sides:

-2x + 4 > 12
    - 4   -4
————————————
-2x     >  8

So we have 

    -2x > 8

Now we divide both sides by -2,
but we now remember the main difference
between solving an INEQUALITY and solving
an EQUATION.  When we solve an INEQUALITY
if we divide (or multiply) by a negative
number we always must reverse the direction
of the inequality symbol. So when we divide 
both sides by -2, we reverse the inequality 
symbol from > to <
:

    -2x  >  8

    -2x      8
   —————  < ———  
     -2     -2

        x < -4

That has this graph:

<================o----------------------------
-8  -7  -6  -5  -4  -3  -2  -1   0   1   2   3

and the interval notation for that is

               (-∞,-4) 

Edwin