Am i correct on # give honest answers and don’t just guess for free

Which value of c would make he following expression completely factored? 8x+cy

Can someone me with these two circle theorem questions asap?

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