Can someone please help me with this also please give answers which are relevant and have an explanation

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.

How many 2/5s are in 1 and 1/2 plz someone me right now

Libby built a fence that was 56 \text { feet}56 feet long over 44 days. she built the same length of fence each day. how many inches of fence did libby build each day?