The price of a 2-hour plumbing repair job is $130 and the price of a 5-hour job is $250. Write an equation for the cost C of a t-hour repair job and use the equation to find the cost of a repair job lasting 7 hours.

Question

Quizplus · Accepted Answer

The cost can be determined by finding the rate per hour and the fixed cost. From the given, for 2 hours, the cost is $130, and for 5 hours, it's $250. The difference ($120) for the additional 3 hours implies a rate of $40 per hour. The fixed cost can be found by subtracting the variable cost (2 hours * $40 = $80) from the total cost for 2 hours, which gives $50. Thus, the equation is C = 40t + 50. For a 7-hour job, the cost is 7 * $40 + $50 = $330.

The Price of a 2-Hour Plumbing Repair Job Is $130