document.write( "Question 1040217: A rectangular pen is built by using 100 ft of fencing. If a river is on one side and no fencing is placed along it, what is the expression of the area of the pen in terms of x? \n" ); document.write( "
Algebra.Com's Answer #655006 by Fombitz(32388)\"\" \"About 
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You haven't defined x.
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