Question level, secondary I am a student asking the question I have no clue how to do this problem. Here is what the professor gave to us: A=LW C=E(2L+2W) + I(PL) Where P = # of partitions E= cost of exterior of fence I = cost of interior of fence C = total cost of fence This is the picture of how the fence is supposed to look. We need to derive a formula and express the area in terms of W and have the fence at a maximum area Mike Hi Mike, From the way you describe the problem I am going to assume that the total cost of the fence C is known, as well as P, E and I. What you don't know are the dimensions of the field, L and W. When you are told to express "A in terms of W", what is expected is an expression for A contains only W and the known quantities C, P, E and I. You have A = LW and hence you need to eliminate L from this expression. Solve the equation C=E(2L+2W) + I(PL) for L and substitute the expression you get into A = WL to get an expression for A that contains no L. I got Finally find the value of W that maximizes A. Cheers, Harley Go to Math Central