Suppose that someone said that the equation connecting points (-1, 1) and (2, 3) is y = 2/3 x + 5/3 This person wants to know whether the line represented by this equation will contain point (6, 9). Identify two ways by which this person can decide whether the graph of the equation contains the point."

Sketch the graph of a quadratic function for which the

related quadratic equation has only one solution. Then,
sketch one that has two solutions. Explain how you
know by looking at the graph the number of solutions
there are.