Question

State the equilibrium condition in terms of cardinal utility analysis in the case of one commodity.

Answer 1

A consumer who aims to maximize utility reaches equilibrium when they buy a quantity of the good such that the marginal utility from the last unit consumed is equal to the price of the good.
In symbolic terms, equilibrium is achieved when:

Mu_x = P_x

where Mu_x = Marginal utility of commodity X.

P_x = Price of commodity X.