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utility function u(x,z) := ln(x+1)+z

MUx=1/(x+1), MUz=1, MRSxz= -1/(x+1)

Evaluate the MRS of u at points where x = 0 or z = 0.

For the case where z=0, find the value of x such that (x, 0) lies on an indifference curve with utility level u*, by writing z as a function of x and u*, and then setting z = 0. The correct answer for z=0 is

For Z U. X MRS =