Hicksian Demand Function

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Derive Hicksian demand for -

$$u(x,y) = ax+ b\ln(y)$$

Explain in words what they mean?

I solved the problem with the Lagrange Multiplier Method and found Hicksian demand for $x$ only.

Solution: Suppose, the expenditure function is -

E = P1x + P2y

Subject to utility function -

u = ax + b ln y

Using Lagrange Multiplier for constrained optimization we get -

L = P_1 x+P_2 y+µ(u-ax-blny)

using first order condition for optimization - ∂L/∂x=P_1-aλ=0 …… (1) ∂L/∂y=P_2-bλ/y=0 ……. (2) ∂L/∂λ=u-ax-blny=0 ……. (3) Now, dividing equation (1) by equation (2) – y=P_1/P_2 .b/a Putting this value in equation (3), we get -

$$x = \frac1a \cdot \left[u - b\ln\left(\frac{P_1b}{P_2a}\right)\right] $$

I do not know how to explain this situation or demand function. Also, I do not understand how to find Hicksian demand for y from this. Is there any alternative method I should have used?