This document discusses consumer utility maximization and budget constraints. It assumes consumers will try to get the most value for their money given limited incomes. The utility maximizing rule is that marginal utility gained from the last money spent on each good should be equal. Formulas show the relationship between marginal utility per price for different goods. Examples then demonstrate how consumers allocate spending across goods X and Y to maximize total utility for different income levels. Indifference curves are introduced to show combinations of goods that provide equal utility.