Final answer:
Generic drugs are approved by the FDA if they are proved to be bioequivalent to the brand-name drug and are less expensive due to the reduced testing required. However, they are not identical to brand-name drugs and may have different inert ingredients.
Step-by-step explanation:
Generic drugs are approved by the FDA if they are proved to be bioequivalent to the brand-name drug. They are less expensive because manufacturers of these drugs do not have to do the extensive testing required of brand-name drugs before marketing. However, generic drugs are not identical to brand-name drugs and often have different inert ingredients.