Knuckles displays the Graphing Method

Step 1	First you have to arrange both the equations into slope intercept form. x+y=4 change to y=-x+4 2x+y=5 change to y=-2x+5
Step 2	Check to make sure y is by it self, in this case it is but if the problem had been 2y=2x+4 you would have to divide 2x+4 by 2 and get y=x+2
Step 3	Since our y is by itself all we have to do is make a graph.
Step 4	By using the graph we see the points meet at (1,3) making our answer x=1 and y=3 although this method can be useful I personaly recommend checking your answer with either substitution or elimination.