Final answer:
To find the demand function for good X when Py = €500 and Y = €10,000, substitute these values into the given equation, resulting in Qdx = -Px + 32000. Graphical analysis can then be used to compare demand and supply curves to determine the equilibrium price and quantity.
Step-by-step explanation:
The student's question relates to determining the demand function for good X given certain values of Py (price of good Y) and Y (income). To solve for the demand function of good X considering Py = €500 and Y = €10,000, we simply substitute these values into the given demand function equation Qdx = -Px + 4Py + 3Y. Accordingly, the new demand function for good X becomes Qdx = -Px + (4*€500) + (3*€10,000), which simplifies to Qdx = -Px + 2000 + 30000, or Qdx = -Px + 32000.
To analyze economic models graphically, students might graph the demand and supply functions to find the equilibrium price and quantity. For example, the reference information shows how to graph these functions and find the equilibrium where the demand curve intersects the supply curve. Here, it shows a demand curve P = 8 - 0.5Qd and a supply curve P = -0.4 + 0.2Qs, with the equilibrium found where Qs = Qd resulting in a price of $2 and a quantity of 12, as predicted by algebra.