Question 1169599
"It is surrounded by a pathway of the same width."

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Which or what same width?  Both "widths" are equal?  You did not say, "of uniform width".  


If you mean to say this way:
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park is 200m long and 12m wide.It is surrounded by a pathway of uniform width. 
 Suppose the total area of the park and the pathway is 25,956m².  Find the width of the pathway surrounding the park.
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Let u be this uniform width for the surrounding pathway.
{{{(200+2u)(12+2u)=25956}}}


{{{(u+100)(u+6)=6489}}}

{{{u^2+106u-5889=0}}}

.
.
{{{u=-53+sqrt(8698)}}}