A company distributes its product by train and by truck. The cost of distributing by train can be modeled as −0.06x2 + 32x − 100, and the cost of distributing by truck can be modeled as −0.04x2 + 26x − 170, where x is the number of tons of product distributed. Write a polynomial that represents the difference between the cost of distributing by train and the cost of distributing by truck.