Solve the inequality 2x+1 x +4 (b) Prove that 32n+1, for n 1. x-1 x+2 (c) Use the Binomial Theorem to prove that (1 + 5 n 4 5n E = 3 > 53 25 1 8 25n' (d) Determine the least upper bound of the set 8 {3-7953 for n 1. 2,...}. n : n = 1, 2, .