Need help on this, keep getting the wrong answer according to back of the book. Assignment is not due just reg hw. If done right ill give you a super rating!

10. For the given functions find and classify all critical points and then evaluate z at those points (6 marks each). a. z = f(x, y)=2xz +=y' + 3xy - 10x - 9y + 216. The cost for producing x number of simple calculators and y units of scientific calculators is given by the following function: C(qaqb) = 49. + 0.054295 + 10q, +600. Determine the marginal cost (Cx(qa, q:); Cy(qa, q:)) with respect to both q, and q5- And interpret both marginal costs when qa = 20 and q, = 30