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Find x + y + z.

 

 Dec 3, 2019
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Find x + y + z.

 

\(\begin{array}{|rcll|} \hline (x+y)^2 &=& 9^2+12^2 \\ (x+y)^2 &=& 225 \\ \mathbf{x+y} &=& \mathbf{15} \\ \hline \end{array} \)

\(\begin{array}{|rcll|} \hline z &=& \dfrac{9*12}{x+y} \quad | \quad x+y = 15 \\ z &=& \dfrac{9*12}{15} \\ z &=& \dfrac{3*12}{5} \\ \mathbf{z} &=& \dfrac{36}{5} \\ \hline \end{array}\)

\(\begin{array}{|rcll|} \hline 9^2 &=& x(x+y) \quad | \quad x+y = 15 \\ 81 &=& 15x \\ x &=&\dfrac{81}{15} \\ \mathbf{x} &=& \dfrac{27}{5} \\\\ y &=& 15-x \\ y &=& 15-\dfrac{27}{5} \\ \mathbf{y} &=& \dfrac{48}{5} \\ \hline \end{array}\)

 

\(\begin{array}{|rcll|} \hline x+y+z &=& (x+y) + z \\ &=& 15 + z \\ &=& 15 + \dfrac{36}{5} \\ \mathbf{x+y+z} &=& \mathbf{\dfrac{111}{5}} \\ \hline \end{array}\)

 

laugh

 Dec 3, 2019

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