Answer
The porch is 8 by 40.
Work Step by Step
Note, the 5 step process is as follows:
(1) Familiarize yourself with the problem.
(2) Translate the problem into Algebra.
(3) Solve.
(4) Check. Note, if we want to check a solution, we would plug it back into the equation and check that the equation yields a true statement.
(5) State the answer.
After becoming familiar with the problem, we find:
$$320=(w)(5w) \\ 320 = 5w^2 \\ w=8\\ So: \\ l=5(8)=40$$
The porch is 8 by 40.