Question 1122733
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<pre>
Let W be the width, in feet.


Then the length is  (135-W) ft.


The money equation is


4*(2W) + 24*(135-W) = 2280.


Simplify and solve for W:


8W + 24*135 - 24W = 2280

24*135 - 2280 = 24W - 8W 

960 = 16W  ====>  W = {{{960/16}}} = 60.


<U>Anwer</U>.  The width is 60 ft;  the length is 135-60 = 75 ft.


<U>Check</U>.  Perimeter = 2*(60 + 75) = 270 ft.             ! Correct ! 

        The cost = 4*(2*60) + 24*75 = 2280 dollars.   ! Correct ! 
</pre>

Solved.


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<U>Be aware</U> !   &nbsp;&nbsp;The solution by &nbsp;@Boreal &nbsp;is incorrect.