от BTK Strangler » 19 Фев 2014, 15:07
[tex]\begin{array}{|l}2x-\frac{z}{6 }+2x-\frac{z}{9 }=3 \\ \underbrace{x+\frac{z}{3 }-\frac{x-z}{ 4}}_{12}=4 \end{array}[/tex]
[tex]\begin{array}{|l} \underbrace{4x-\frac{z}{6 }-\frac{z}{9 }}_{18}=3 \\ \frac{12x+4z-3(x-z)}{12 }=4 \end{array}[/tex]
[tex]\begin{array}{|l}72x-3z-2z=54\\9x+7z=48 \text{ умножаваме с } -8 \end{array}[/tex]
[tex]\begin{array}{|l}72x-5z=54\\-72x-56z=-384\end{array}[/tex]
Сега събираме двете уравнения:
[tex]\begin{array}{|l}-61z=-330\\9x+7z=48 \end{array} \Rightarrow z=\frac{330}{ 61}, \vspace{} x=\frac{206}{183 }[/tex]