Examples of functions and non-functions in algebra, marked with checkmarks and X's to illustrate the concept.
A math educational slide titled "What is a Function?" showing various equations with green checkmarks for functions and red X's for non-functions, illustrating examples like y = 3/5x - 11 (function) and (x - 2)²/4 - (y + 7)²/16 = 25 (not a function), with the Study.com logo in the corner.