Which of these are equivalent to (10 x 18) (10 x s)

Joey is buying plants for his garden. he wants to have at least twice as many flowering plants as nonflowering plants and a minimum of 36 plants in his garden. flowering plants sell for $8, and nonflowering plants sell for $5. joey wants to purchase a combination of plants that minimizes cost. let x represent the number of flowering plants and y represent the number of nonflowering plants.