Системни уравнения

[Гост]

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[ammornil]

[tex]\begin{array}{|l} x + y -z= 1 \\ x + y = 2 \\ 3x-y-z=1 \end{array} \Rightarrow \begin{array}{|l} 2 -z= 1 \\ y = 2-x \\ 3x-y-z=1 \end{array} \Rightarrow \begin{array}{|l}z=3 \\ y = 2-x \\ 3x-(2-x)-3=1 \end{array} \Rightarrow \begin{array}{|l} z=3 \\ y = 2-x \\ 3x-2+x-3=1 \end{array} \Rightarrow \begin{array}{|l} z=3 \\ y = 2-x \\ 4x=6 \end{array} \Rightarrow[/tex]

[tex]\begin{array}{|l} z=3 \\ y = 2-x \\ x=\frac{3}{2}=1\frac{1}{2} \end{array} \Rightarrow \begin{array}{|l} z=3 \\ y = 2-1\frac{1}{2}=\frac{1}{2} \\ x=1\frac{1}{2} \end{array} \Rightarrow \begin{array}{|l} x= 1\frac{1}{2} \\ y ={\Large \frac{1}{2}} \\ z=3 \end{array}[/tex]