PLEASE HELP ME!

Respond to the following discussion prompt.

Springs are versatile objects used in many everyday devices. The functions they perform vary according to the situation. Think about some devices or situations where expansion or compression of the springs is in direct proportion to the force applied to them, and respond to both of the prompts. Number your responses to match the prompts. Cite your sources if you search on the internet.

1.) Discuss two examples of the use of springs in real-life situations or devices for functions other than weighing.

2.) Elaborate on the mechanisms by which the springs help the devices function in your examples.

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.

Carla was trying to decide what to do saturday evening. she has $100 available to spend for the evening. she has narrowed her choices down to these events: braves game, a concert of an artist she likes, or the georgia aquarium. admission to the braves game is $25, hot dogs cost $10, sodas cost $5. the concert costs $25 for admission, $20 for a souvernir t-shirt, and $10 for a soda. the georgia aquarium has the show of a lifetime with an all you can eat and drink that costs $100. carla does not want to take any driving chances, so in addition to the cost of the aquarium, she will also need to pay for her uber/lyft, which is $15 each way. which option should carla choose if she wants to spend the least? based on that choice, what then is carla's oppotunity cost? fully explain your answer in at least one paragraph.

What is the answer to the question 5x+2x