Ronald is setting up an aquarium in his new office. at one pet store, fish cost $2 each and an aquarium cost $40. at another pet store, fish cost $3 each and an aquarium cost $36. write and solve a system of equations to represent the cost of x fish and an aquarium at each store. solve this the system. what does this solution represent? if ronald wants 5 fish, from which pet store should he buy his aquarium