Cost of each plant both buys = $7 No. of plants Stephanie wants to buy = s Total cost of plants bought by Stephanie = 7·s No. of plants Diego wants to buy = d Total cost of plants bought by Diego = 7·d Total cost = 7·s + 7·d = 7·(s + d) Discount applied through coupon = $25 So, Total cost of all their plants with discount = 7·(s + d) - 25
