82. Budget: Costs. The marching band at a university is ordering some additional uniforms to replace existing uniforms that are worn out. If the band orders 50 or fewer, the cost is $176.12 per uniform. If it orders more than 50 but fewer than 100, the cost is $159.73 per uniform. Find the cost function C(x) as a function of the number of new uniforms x ordered.

In Example 3, if the accountant earns a profit of 100 on each individual return and a profit of 175 on each business return, find the maximum profit. An accountant prepares tax returns for individuals and for small businesses. On average, each individual return requires 3 hours of her time and 1 hour of computer time. Each business return requires 4 hours of her time and 2 hours of computer time. Because of other business considerations, her time is limited to 240 hours, and the computer time is limited to 100 hours. If she earns a profit of 80 on each individual return and a profit of 150 on each business return, how many returns of each type should she prepare to maximize her profit?

3. A sporting goods store sells 64 tennis rackets per month at $90$ each. The owners estimate that for each $5 increase in price, they will sell 2 fewer tennis rackets per month. Find the price per tennis racket that will maximize revenue.

9. A treadmill that cost a retailer $420 less 33 1/3%, 20% and 5% was sold to include operating expenses at 25% of selling price and an operating profit of 35% of selling price. What is the breakeven price?