How do we define equations for different types of resources?

Equations for different types of resources can be defined by taking into consideration factors such as the quantity, quality, availability, cost, and amount of effort required to produce or acquire the resource. For example, an equation for water resources could include the cost to produce or acquire the water, the quantity needed, and the amount of energy required to extract or purify the water. Similarly, an equation for renewable energy sources could include the amount of energy generated by the source, the availability and cost of the source, and the method used to capture and store the energy. By taking into account all these variables, equations can accurately represent the value and cost of each type of resource.