Final answer:
This question pertains to creating and interpreting supply and demand graphs within economics to find market equilibrium, verified through algebraic solutions.
Step-by-step explanation:
The student's question involves creating and analyzing supply and demand graphs in an economic context. When we graph the provided demand equation P = 8 - 0.5Qd and the supply equation P = -0.4 + 0.2Qs on a price-quantity graph, we get two lines that represent the respective demand curve and supply curve. The point where both curves intersect represents the market equilibrium, where the quantity demanded (Qd) equals the quantity supplied (Qs). In this scenario, the algebra indicates that this equilibrium price is $2 and the equilibrium quantity is 12 pizzas. Graphing these curves helps to visually validate the algebraic solution.