1) \( 2 x_{1}-3 x_{2}=19 \)
2) \( 4 x_{1} \quad-8 x_{3}=20 \)
3) \( 5 x_{2}-4 x_{3}=-7 \quad | \cdot 2 \)
2) \( 4 x_{1} \quad-8 x_{3}=20 \)
3) \( 10 x_{2}-8 x_{3}=-14 \)
2)-3)' \( 4 x_{1}-10 x_{2}=34 \)
\( \Rightarrow A) ~ {2 x_{1}-3 x_{2}=19 \quad |·2} \)
\( \Rightarrow B) ~ 4x_1 - 10x_2 = 34 \)
\( A)' ~ 4x_1 - 6x_2 = 38 \)
\( B) ~ 4x_1 - 10 x_2 = 34 \)
\( {A^{\prime}-B}) \quad {4 x_{2}=4 \quad \Rightarrow x_{2}=1} \)
in 1) \( 2 x_{1}-3=19 \quad \Rightarrow x_{1}=11 \)
in 2) \( 44-8 x_{3}=20 \Rightarrow x_{3}=3 \)