The graph of a "linear function" (x and y appear only to first power and not in any functions like "sin(x)" or "log(y)") is a straight line. A straight line is determined by two points. So determine two points by choosing a value of x or y and solving for the other. Mark those two points on the graph and draw the line thorough them.
Here, one function is 2x+ y= 2. If we choose x= 0 (just because it is easy) we have 2(0)+ y= y= 2. So one point is (0, 2). If we choose y= 0, we have 2x+ 0= 2x= 2 so x= 1. Another point is (1, 0). Mark the points (0, 2) and (1, 0) and draw the line through them. (One of the three graphs you show has a line that passes through both (0, 2) and (1, 0).)
The other is x- y= 1. If we choose x= 0 we have -y= 1 so y= -1. One point on the graph is (0, -1). If y= 0 we have x- 0= x= 1. A second point on the graph is (1, 0). Mark those points on the graph and draw the line between them. It should be obvious where the two lines cross and what x, y values satisfy both equations.