Here are two views about how to symbolically represent two linear functions plotted in the {x,y} plane.[br][br][color=#0000ff]1) A pair of simultaneous linear equations of the form ax + by = c and Ax + By = C, or[/color][br][br][color=#6aa84f]2) A single equation of the form px + q = Px + Q.[/color][br][br][color=#0000ff]If you regard the two linear functions as a pair of simultaneous linear equations then the solution set is the [i][b]point in the {x,y} plane[/b][/i] where the graphs of ax + by = c and Ax + By = C intersect.[/color][br][color=#6aa84f][br]If you regard the two linear functions as a single equation of the form ax + by = c and Ax + By =C then the solution set is the [i][b]point on the x axis[/b][/i] whose x coordinate is the x coordinate of the intersection point of the two graphs.[br][/color][br]Which formulation do you prefer ? Why ? [br][br][color=#ff0000][i][b]What problems could/would you pose to your students based on this applet ?[/b][/i][/color]