You cannot solve it.
You can only find two random points on it and draw a line through them.
Start off by choosing two random x values.
For example, I choose x = 0 and x = 1.
When x = 0, y = 4(0) - 1 = 0 - 1 = -1
This means (0, -1) is a point on the graph.
When x = 1, y = 4(1) - 1 = 4 - 1 = 3
This means (1, 3) is a point on the graph.
Next I draw a straight line through the points (0, -1) and (1, 3), and I am done.