Please help.. Geometry.. No links please!

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.

What is the simplified form of (3.25x10^3)(7.8x10^6) written in scientific notation?

Graph the linear function using the slooe and y intercept