Question 706574
<pre>
No, you don't need to graph.  Just plug them in and see
if you get a true numerical equation or a false one:

2x - y = 6

3.)  x = 4, y = 2                5.) x = 4, y = -2

Plug those in                    Plug those in

    2x - y = 6                        2x - y = 6
2(4) - (2) = 6                   2(4) - (-2) = 6
     8 - 2 = 6                         8 + 2 = 6
         6 = 6                            10 = 6

That's true so x = 4,            That's false so x = 4,               
y = 2 is a solution.             y = -2 is NOT a solution.

Edwin</pre>