The concepts of price, income and cross price elasticity of demand are of little relevance in explaining the pricing decisions of business organisations. Explain and discuss with reference on recent example.

The concepts of price, income and cross price elasticity of demand are of little relevance in explaining the pricing decisions of business organisations. Explain and discuss with reference on recent example.
Please by answering please explain elastic & inelastic using theory, link to differentiation in business, and explain how change in price can affect profitability-demand etc and use examples from real life (eg airline industry, restaurants etc)