1. The problem statement, all variables and given/known data A total of x feet of fencing is to form 3 sides of a level rectangular yard. What is the maximum possible area of the yard, in terms of x? 3. The attempt at a solution So far I have 2 sides of the yard is denoted by y, and one side is denoted by z. Then, 2y+z=x We want to maximize the Area=yz Now, do I substitute one of the variables in the Area equation to get the answer? Then I know I need to differentiate, but with respect to what? I'm confused here.