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Your community wants to put a square fountain in a park. Around the fountain will be a sidewalk that is 3.5 ft wide. The total area that the fountain and sidewalk can be is 700 ft2. What are the dimensions of the fountain?

 Mar 9, 2015

Best Answer 

 #1
avatar+130516 
+5

Let x be each side of the fountain....so we have

L x W = 700

(x + 7)(x + 7)  = 700  simplify

x^2 + 14x + 49 = 700

x^2 + 14x - 651  = 0

Using the on-site solver, we have

$${{\mathtt{x}}}^{{\mathtt{2}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{14}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,-\,}}{\mathtt{651}} = {\mathtt{0}} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = {\mathtt{\,-\,}}{\mathtt{10}}{\mathtt{\,\times\,}}{\sqrt{{\mathtt{7}}}}{\mathtt{\,-\,}}{\mathtt{7}}\\
{\mathtt{x}} = {\mathtt{10}}{\mathtt{\,\times\,}}{\sqrt{{\mathtt{7}}}}{\mathtt{\,-\,}}{\mathtt{7}}\\
\end{array} \right\} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = -{\mathtt{33.457\: \!513\: \!110\: \!645\: \!905\: \!9}}\\
{\mathtt{x}} = {\mathtt{19.457\: \!513\: \!110\: \!645\: \!905\: \!9}}\\
\end{array} \right\}$$

So...each side of the fountain is about 19.46 ft

And the area is (19.46)^2  = 378.7 sq ft

 

  

 Mar 9, 2015
 #1
avatar+130516 
+5
Best Answer

Let x be each side of the fountain....so we have

L x W = 700

(x + 7)(x + 7)  = 700  simplify

x^2 + 14x + 49 = 700

x^2 + 14x - 651  = 0

Using the on-site solver, we have

$${{\mathtt{x}}}^{{\mathtt{2}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{14}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,-\,}}{\mathtt{651}} = {\mathtt{0}} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = {\mathtt{\,-\,}}{\mathtt{10}}{\mathtt{\,\times\,}}{\sqrt{{\mathtt{7}}}}{\mathtt{\,-\,}}{\mathtt{7}}\\
{\mathtt{x}} = {\mathtt{10}}{\mathtt{\,\times\,}}{\sqrt{{\mathtt{7}}}}{\mathtt{\,-\,}}{\mathtt{7}}\\
\end{array} \right\} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = -{\mathtt{33.457\: \!513\: \!110\: \!645\: \!905\: \!9}}\\
{\mathtt{x}} = {\mathtt{19.457\: \!513\: \!110\: \!645\: \!905\: \!9}}\\
\end{array} \right\}$$

So...each side of the fountain is about 19.46 ft

And the area is (19.46)^2  = 378.7 sq ft

 

  

CPhill Mar 9, 2015

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