The desk is 6 by 3.
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: $$18=(w)(2w) \\ 9= w^2 \\ w=3\\ So: \\ l=(3)(2)=6$$ The desk is 6 by 3.