The total profit (in dollars) from the sale of $x$ answering machines is $$P(x) = 20 x - 0.6 x^2 - 220.$$
(A) Find the exact profit from the sale of the 26th machine.
Exact Profit on 26th machine =
(B) Use the marginal profit to approximate the profit from the sale of the 26th machine.
Approx. profit on 26th machine =