a) The variables p and q are connected by the formula pea +48e9 +6. i) Find the exact values of q when p = 20. ii) Find dp dq and dp dq2 and hence show that the equation dp P- = 0 dq has no solutions. b) Express log3 (9x3) in terms of log3x. c) If 12t6u32tu-5 = =2u2 243t1510 x 8tu Express t in terms of u.