Graphs usually show restrictions with a solid line or dashed line.
The solid line includeds "equal to" and the dashed line "doesn't".
So, y <= x would be graphed with a solid line.
y >= 3/4x -1 would also be a solid line.
If all you have is a shaded area, normally you will pick the points that intercept the x and y axis. This will give points:
(x1, 0) for the y intercept and (0, y2) for the x intercept.
Then you will solve for the slope using the equation:
(y2-y1) / (x2-x1). Since we are using the x and y intercepts,
(y2 - 0) / (0-x1) for the slope.
Now you can put that into an equation:
y = mx+b where m is the slope, and b is the y intercept.
You will be able to write the inequality based on a solid or dashed line.
Regards,
Mysstere