1. The demand for good X has been estimated by Qx^d = 12 3Px + 4Py. Suppose that good X sells at $2 per unit and good Y sells for $1 per unit. Calculate the own price elasticity.
2. Suppose Qx^d = 10,000 2 Px + 3 Py 4.5M, where Px = $100, Py = $50, and M = $2,000. Compute for the own price elasticity of demand.
3. Suppose the demand function is Qx^d = 100 8Px + 6Py - M. If Px = 4 php, Py = $2, and M = $10, determine the cross-price elasticity of good x with respect to the price of good y.
4. Suppose the demand function is given by Qx^d = 10Px^0.9 Py^0.5 M^0.22 H. Calculate the cross-price elasticity between goods x and y.

Please don't just show answer, show solution and possibly explanation as to how you derive.