Define variables and write systems of equations for the situation. Solve using substitution. Suppose you want to join a video store. Big video offers a special discount card that costs $9.99 per year. With the discount card, each video rental costs $2.49. A discount card from Main Street Video cost $20.49 per year. With the Main Street Video discount card, each video rental costs $1.79. After how many video rentals is the cost the same? A. 17 B. 15 C. 9 D. 10. Please select the best answer from the choices provided.