👤

Sa se rezolve sistemul de ecuatii
[tex] 2x - \frac{3y - 2}{5} egal \: 3 \\ 3y + \frac{2x + 3}{3} egal - \frac{4}{3}[/tex]


Răspuns :

[tex]\left\{\begin{matrix}
2x - \frac{3y - 2}{5} = 3 \: | \times 5& \\ \\
3y + \frac{2x + 3}{3} = - \frac{4}{3} | \times 3 &
\end{matrix}\right.[/tex]

[tex]=\left\{\begin{matrix}
10x - 3y + 2 = 15 & \\ \\
9y + 2x + 3 = - 4&
\end{matrix}\right.[/tex]

[tex]=\left\{\begin{matrix}
10x - 3y = 15 - 2 & \\ \\
2x + 9y = - 4 - 3&
\end{matrix}\right.[/tex]

[tex]=\left\{\begin{matrix}
10x - 3y = 13 \: | \times 3& \\ \\
2x + 9y = - 7&
\end{matrix}\right.[/tex]

[tex]=\left\{\begin{matrix}
30x - 9y = 39 & \\ \\
2x + 9y = - 7 & \end{matrix}\right.[/tex]

[tex]30x + 2x - 9y + 9y = 39 - 7[/tex]

[tex]32x = 32 \: | \div 32[/tex]

[tex]x = 1[/tex]

[tex]2x + 9y = - 7[/tex]

[tex]2 \times 1 + 9y = - 7[/tex]

[tex]2 + 9y = - 7[/tex]

[tex]9y = - 7 - 2[/tex]

[tex]9y = - 9 \: | \div 9[/tex]

[tex]y = - 1[/tex]

[tex]S=\left\{(x,y)\right\}=\left\{(1,-1)\right\}[/tex]