Răspuns:
[tex]\boldsymbol{ \red{ S = \bigg\{\bigg(-\dfrac{1}{3} ; -6\bigg)\bigg\}}}[/tex]
Metoda reducerii
[tex]\begin{cases} 9x-3y=15\\3x-7y=41 \ \big|\cdot(-3)\end{cases} \Rightarrow \begin{cases} 9x-3y=15\\-9x+21y=-123 \ \big|\cdot(-3)\end{cases}\\[/tex]
[tex]-3y+21y=15-123 \Rightarrow 18y = - 108 \Rightarrow y = - 6[/tex]
[tex]3x-7(-6) = 41 \Rightarrow 3x=41-42 \Rightarrow 3x=-1 \Rightarrow x = -\dfrac{1}{3}[/tex]
Soluția sistemului este:
[tex]S = \bigg\{\bigg(-\dfrac{1}{3} ; -6\bigg)\bigg\}[/tex]
