Final answer:
The Inverse Demand-Supply Solver is the commonly used tool to determine the inverse relationship between demand and supply in economics.
Step-by-step explanation:
The tool commonly used to determine the inverse relationship between demand and supply in economics is the Inverse Demand-Supply Solver. This tool helps in calculating the equilibrium price and quantity by analyzing the demand and supply curves. It takes into account the factors affecting demand and supply, such as price, quantity, and elasticity, to find the point where the demand is equal to the supply.