Help in solving the questions below kindly. Been having a lot of trouble in understanding this. Include explanations in your working for full reward. Thanks in advance.

Prove that var( X ) = EX - - 421. Consider the following constrained two-period optimization problem: max u(C1, C2) = - exp(-701) - Bexp(-Yc2) (1) 1 subject to: ci + R (2) where y > 0 is the coefficient of absolute risk aversion (CARA), BE (0, 1) is the discount factor, (C1, c2) is the optimal bundle of consumption in periods 1 and 2, I is the given total income during the two periods, R is the gross interest rate. (a) Set up the Lagrangian function for the above optimization problem, and derive the first order conditions.Solve the following constrained optimization problem: maxx* + 2y, subject to: x2 +y'