For each expression below, answer the following:
(a) State whether it is a polynomial in x. If it is not, write "Not a polynomial".
(b) If it is a polynomial, write its degree and state whether it is a monomial, binomial or trinomial.
(i) 2x−1+4
(ii) 7x3+5x2−8x
(iii) 5x4y−2xy3+9