The sequence of positive integers is arranged in the pattern below. Row 1: 1, 2, 3 Row 2: 4, 5, 6 Row 3: 7, 8, 9 Row 4: 10, 11, 12 ... Row n: ..., 3n-1

1. (a)Complete Row n.[1]
2. (b)(i)The table shows some results obtained from this pattern. Row number: 1, 2, 3, 4, n. Square of the middle number in the row: 4, 25, 64, x. Product of the first and the last number in the row: 3, 24, 63, y. Complete the column for Row number 4.[1]
3. (b)(ii)Find an expression, in terms of n, for y.[1]
4. (b)(iii)Show that x – y is always equal to 1.[2]