Dicken's Hardware sells incandescent and CFL light bulbs. Yesterday they sold 18 incandescent bulbs and 24 CFL bulbs for total sales of $132. Part A: Let x represent the cost of an incandescent bulb and let y represent the cost of a CFL bulb. Write an equation or inequality to represent the situation. Explain how you decided to use an equation or inequality.
Part B: A CFL bulb cost $4. Use this information and your equation or inequality from part a to find the cost of an incandescent bulb. Show your work and explain what your answer means in the context of the problem.