you can buy 5 cans for green beans at the village market for $3.20. you can buy 10 of the same can of beans at Sam's Club for $8.10. which place is the better buy

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.

The number of fish in a lake can be modeled by the exponential regression equation y=14.08 x 2.08^x where x represents the year

Ijust need these 2 questions answered (the second pic is just confirmation i'm not confident in that answer)