[4 marks] Let (un)-(ul, u2, u3, u4, xel ui using the formula for the sum of an arithmetic series (see Formula Sheet). 4) ) = { 1, 3, 5, 7, 9, } be an arithmetic series with al and d-2. Find } be a geometric series with al and r-2. Find v [5 marks] Let (Vin)-(vl, v2, v3, v4, using the formula for the sum of a geometric series (see Formula Sheet). 5) ) = { 1, 2, 4, 8, 6) [6 marks] Find the following sums using the formula sheet: b) .112