F(x)=x+8 is it linear

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 table shows a proportional relationship between miles traveled and gas used?

Which of the following is closest to 32.9 x 7.5? a: 232 b: 259 c: 220 d: 265