An auto company's sales volume can be modeled by 7.8x? + 3.2x + 3.5, and its cost
can be modeled by 3.4x2 - 0.8x + 3.5, where o represents the number of cars
produced, and y stands for money in thousand dollars. We can calculate the company's
net profit by subtracting cost from sales. Find the polynomial which models the
company's sales in thousands of dollars.