Constrained Consumer Choice: Here the budget constraint and utility/preference discussions come together to describe the solution to the consumer’s problem.  The search is on for the ‘best bundle of goods that the consumer can afford’ – which, of course, occurs at a tangency point between the budget line and an indifference curve.  As in previous sections, an initial focus on perfect substitutes and perfect complements helps emphasize the intuition of constrained optimization without getting too tangled up in the mathematics.