Final answer:
Complementary goods such as personal computers and printers have a directly linked demand; when the price of PCs rises, it reduces the demand for printers. In contrast to complements, substitute goods like tablets can replace other products like laptops, affecting the demand for the other. The law of demand and the movement of the demand curve graphically represent these relationships.
Step-by-step explanation:
The subject in question here is complementary goods in the context of economics and business studies. Personal computers and printers are considered complementary because they are often used together; the use of one enhances the use or value of the other. When the price of personal computers increases, it leads to a decrease in the quantity demanded of personal computers due to the law of demand, which in turn leads to a decrease in the demand for printers. In contrast, a substitute is a good or service that can be used in place of another. An example provided is the increased availability and reduced price of tablets, a substitute for laptops, which results in a decrease in demand for laptops, demonstrated by a leftward shift in the demand curve for laptops. A higher price for a substitute (like if tablets were to increase in price) would have the reverse effect, potentially increasing demand for the other product (laptops).