(d) (i) Factorise the quadratic expression x² + 3x - 28. 22 (ii) Use your answer to part (d) (i) to solve the quadratic equation x² + 3x - 28 = 0, showing each step in your reasoning. Check that your solution is correct. (e) A student writes down the following piece of work, which contains an error in the reasoning. The equation is: y²-19y=0 y² = 19y Add 19y to each side: Divide each side By y: y = 19 (i) Substitute y = 19 into the left-hand side of the equation y²-19y = 0, and explain why this shows that y = 19 is indeed a solution of the equation. (ii) Write out a complete solution of the equation y2 - 19y = 0. (iii) Explain, as if directly to the student, why their solution is inadequate. (f) Solve the following equation, checking that your solution is correct: 24 72 <- x+3 9