UNsolve 2 variable linear equations & inequalities

The solution set of a linear equation in 2 variables, f(x,y) = 0, is a straight line in the x,y plane. The solution set of a linear inequality is all the points in the x,y plane on one side of that line. To UNsolve a linear equation or inequality, use the a, b and c sliders in the rightmost panel to fix the solution set. The left panel will show the solution set. The center panel will show you a linear equation or inequality that has that solution set. You can use the s slider in the rightmost panel to see other linear equations or inequalities that have the same solution set. For a given solution set, how many equations or inequalities are there that have that solution set? How do you know? Can you prove it?