So let's add variables according to the ratio: 3n + 2n = <span>£80 5n = </span><span>£80 n = 16 3(16):2(16) 48:32 Tom gets </span>£48, and Jerry gets <span>£32</span>
and so on. Notice how the subscript on a on the right side and the coefficient multiplied by 13 add up to n (n - 2 + 2 = n; n - 3 + 3 = n; and so on). If we continue the pattern, we'll end up with
so that the explicit rule for the n-th term in the sequence is