Question

Part A: Explain why the x-coordinates of the points where the graphs of the equations y = 4x and y = 2x−2 intersect are the solutions of the equation 4x = 2x−2. (4 points)

Answer 1

The place where two equations intersect, has a certain value of y. This means that in the intersection point, the y-values of both expressions are the same, so y = y. Since y is also represented by the following equations, y = 4x and y = 2x - 2, the x-value of the intersection point is 4x = 2x - 2.