Consider the polynomial P (x) = 2x + 19x3 + 42x2 - 19x - 39. (i) Divide P (a) by a2 + 5ac + 4 using long division and write the division algorithm for P (ac). (ii) Set Q (a) = P (x) - 5. Using part (i) above to write Q (a) as a product (multiplication) of two quadratic polynomials. (iii) Now factorise the two quadratic polyomials in part (ii) above, and so then completely factorise Q (a) (into linear factors). Find all the roots of Q (ac). (iv) Draw the sign table and the graph of Q (a)