5x-2y=1 is a linear equation so is a straight line graph. We need two points to draw a unique straight line. If we find the intercepts we can draw a line through them. That will be the required graph.
To find the x-intercept, plug in y=0: 5x=1, x=0.2 (or ⅕).
To find the y-intercept, plug in x=0: -2y=1, y=-0.5 (or -½).
To show these intercepts clearly you need a suitable scale because both intercepts are close to zero.
Since ⅕=2/10 and ½=5/10, a good scale for both axes would be to use 10 subdivisions of 1 as shown in the example below: