Система

[Гост]

[tex]\begin{array}{|l} 4u + 21v = 98 \\ 6u - 35v = 14 \end{array}[/tex]

[ammornil]

[tex]\begin{array}{|l} 4u + 21v = 98 \\ 6u - 35v = 14 \end{array}[/tex]

[tex]\begin{array}{|l} 4u + 21v = 98 |.5 \\ 6u - 35v = 14 |.3 \end{array} \Rightarrow \begin{array}{|l} 20u+105v=490 \\ 18u - 105v = 42 \end{array} \Rightarrow \begin{array}{|l} 20u+105v+(18u - 105v)=490+42 \\ 4u + 21v = 98 \end{array} \Rightarrow[/tex]

[tex]\begin{array}{|l} 38u=532 \\ 4u + 21v = 98 \end{array} \Rightarrow \begin{array}{|l} u=14 \\ 4.14 + 21v = 98 \end{array} \Rightarrow \begin{array}{|l} u=14 \\ 21v=98-56 \end{array} \Rightarrow \begin{array}{|l} u=14 \\ v=2 \end{array}[/tex]