Question 54904
<pre><font size = 5><b>      2x + 9 = x + 1

We want to get rid of all terms on the left which
DO NOT contain x, and get rid of all terms on the
right which DO contain x.

The + 9 is on the left side and does not contain x
so we want to get rid of it by adding its opposite
-9 to both sides:

      2x + 9 = x + 1
         - 9     - 9
    ------------------
      2x     = x - 8

The term x is on the right side and does contain x
so we want to get rid of it by adding its opposite,
-x to both sides:   

      2x     = x - 8
      -x      -x
    ------------------
       x     =    -8

Edwin</pre>