Adam wants to buy a new computer that costs $510. He earns $8.50 per hour working for his aunt. Enter an equation using the variable x that can be used to solve for the number of hours Adam must work to buy the computer.
Pls help

Gravel is being dumped from a conveyor belt at a rate of 25 ft3/min, and its coarseness is such that it forms a pile in the shape of a cone whose base diameter and height are always equal. how fast is the height of the pile increasing when the pile is 14 ft high? (round your answer to two decimal places.) ft/min