Question 6 - 25 marks This question is based on your work on MU12s w to and including Unit 9. (a) (i) For the finite arithmetie sequence 4,9,14,69 write down the first term a, the common difference d and the last term L, and hence find the nuibber of terms n of the sequence. Check that your answer is correct. [3] (ii) Use an appropriate formula from Unit 9, Subection 1.1 to find the sum of the arithmetic sequence in part (a)(i). [2] (b) Expand the brackets in the following expressions. (i) (7x5)(3x+4) [2] (ii) (4a7b)2 [2] (c) Factorise 16h249k2. [2] (d) (i) Factorise the quadratic expression x26x55. [2] (ii) Use your answer to part (d)(i) to solve the quadratic oquation x26x550, showing each step in your reasoning. Check that your solution is correct. [2] (e) A student writes down the following piece of work which contains an error in their reasoning. The equation is: y223y=0 Add 23y to each side: y2=23y Divide each side By y:y=23 (i) Substitute y23 into the left-hand side of the equation y223y=0, and explain why this shows that y23 is indeed a solution of the equation. [2] (ii) Write out a complete solution of the equation y223y0. (iii) Explain, as if directly to the student, why their solution is inadequate. [1] (f) Solve the following equation, checking that your solution is correct: 6x16x+356 Question 7 - 5 marks A score out of 5 marks for good mathematical communication over the entire TMA will be recorded under Question 7. [5]