<PRE><B>Question 208617</B>

Let length = 3x - 20 
Let width = x 
The perimeter is 80 

Use the formula: P = 2L + 2W as step one. 

Here is the set up: 
80 = 2(3x - 20) + 2(x) 

When you find x, this will be your width. Then go back to 3x - 20, plug your value for x and simplify to find your length. 

Can you finish now? 
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