A garden shop determines the demand function q = D(x) = - 4x + 400 20x+9 during early summer for tomato plants where q is the number of plants sold per day when the price is x dollars per plant. (a) Find the elasticity. (b) Find the elasticity when x = 5. (c) At $5 per plant, will a small increase in price cause the total revenue to increase or decrease? (a) The elasticity is (b) When x=5, the elasticity is (Simplify your answer. Type an integer or a fraction) (c) Fill in the blank below. At $5 per plant, a small increase in price will cause the total revenue to