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