Whether two goods are substitutes or complements can be determined by computing the.

cross price elasticity of demand

Explanation:

The cross price elasticity of demand measures the changes in quantity demanded of one good when the price of another good changes.

Substitute goods are goods that can be used instead of another good e.g. coke and pepsi. The cross price elasticity for substitutes is usually positive because an increase in price of one good increases the quantity demanded of the other good.

Complementary goods are goods that have to be consumed or used together. E.g. car and gas. The cross price elasticity for complementary goods are usually negative because an incease in price of one good leads to fall in the quantity demanded of the other good.

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1. avoid them

2. a talk with them

3. ask someone you trust

4. ignore

5. call police