Question

Philip uses 60ft of fencing to build a rectangular dog run. One side of the rectangle is the wall of Philip's house. Which will not need fencing. The total area of the dog run must be at least 440 square feet. What inequality can be solved to find x, the length in feet of the dog run?

Answer 1

x(60 - 2x) ≥ 440

Explanation:

Let the wall of Philip's house is along the width of the rectangular dog run.

Let us assume that the length is L and the width is W.

Then given that

2L + W = 60 .......... (1)

Now, again, it is given that LW ≥ 440

⇒ L(60 - 2L) ≥ 440

⇒ x(60 - 2x) ≥ 440 {Where L = x}

Therefore, this is the inequality that can be solved to find x, the length in feet of the dog run. (Answer)