Formula for revenue
Quantity x price
Equilibrium
Qd = Qs
Average cost
Total cost / number of goods a unit produced
Profit
Total revenue - total expenses
Marginal utility
Total utility - the previous total utility
Marginal cost
Change in cost / change in quantity
Price ratio
Price a / price b
Marginal rate of substitution
Marginal utility of good a / marginal utility of good b