Question

Imi puteti explica cum se rezolva acest sistem? Am nevoie si de punctul a. Va roog​

Answer 1

$\it \begin{cases}\ \it 3(x-1)+2y=5\\ \\ \it -4x+2(y+1)=-4\end{cases} \Rightarrow \begin{cases}\ \it 3x-3+2y=5\\ \\ \it -4x+2y+2=-4\end{cases} \Rightarrow$

$\it \Rightarrow \begin{cases}\ \it 3x+2y=8\\ \\ \it -4x+2y=-6|_{\cdot(-1)}\end{cases} \Rightarrow \begin{cases}\ \it 3x+2y=8\\ \\ \it \ 4x-2y=6\end{cases}\\.\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \rule{80}{0.5}\\.\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 7x\ \ \ \ \Big |\ =14 \Rightarrow x=2$

$\it \begin{cases}\it 3x+2y=8\\ \\ \it x=2\end{cases} \Rightarrow 3\cdot2+2y=8 \Rightarrow 2y=2 \Rightarrow y=1\\ \\ \\ S=\{(2,\ 1)\}$