I need the answer to the second image please help.

The amount of energy it takes to lift a box might be a function of which of the following

What is the value of x in the this question ?

You just purchased two coins at a price of $670 each. because one of the coins is more collectible, you believe that its value will increase at a rate of 7.1 percent per year, while you believe the second coin will only increase at 6.5 percent per year. if you are correct, how much more will the first coin be worth in 15 years?