2. What is the marginal rate of substitution(MRS) for the following utility function? u(x1, x2) = v(x1) + x2

3. Suppose that indifferent curves are described by straight line with a slope b. Given arbitrary prices and income, p1, p2, I, what will the consumer's optimal choices look like?

4. Consider the problem of maximizing u(x, y) = xy on the constraint set h(x, y) = x 2 + y 2 1.