What is -x - (1 + 6x) simplified?

What values of data might affect the statistical measures of spread and center

Suppose that the price p (in dollars) and the weekly sales x (in thousands of units) of a certain commodity satisfy the demand equation 4p cubedplusx squaredequals38 comma 400. determine the rate at which sales are changing at a time when xequals80, pequals20, and the price is falling at the rate of $.20 per week.

Which of the following expressions is equal to 2x^2+8