Question 890970
Area = length * width
Given area = 6000
Length = 2W - 20
.
There are many ways to solve this.  I like the factoring method.
What are the factors of 6000?
Since we're looking for ones fairly close together, let's start at 60.
100,60
Well, that worked.  We don't even need to go any further.  Twice 60 minus 20 is 100.  Isn't the brain a wonderful thing?