Lagrange Multiplier Problem: Explain the Lagrange Multiplier technique for constrained optimization. Use the Lagrange Multiplier method for solving the following problems: a. U=xy, subject to x+2y=2 b. U=x(y+4), subject to x+y=8 c. U=x3yxy, subject to x+y=6 d. U=77+x2, subject to x+y=0