LaShawn wants to buy some music online. There are two plans to choose from. The first plan is a flat rate of $1.29 per download. The second plan has a membership fee of $21, and a fee of $0.99 per download. Let x be the number of downloads and C be the cost. Plan 1: C = 1.29x Plan 2: C=21 + 0.99x A. When are the costs of the two plans equal to each other? Explain. B. What is the y-intercept of the line for each equation? What does it mean in this context? C. What is the constant rate of change for each relationship? What does it mean in this context?