Question

va rog frumos imi trebuie acum!!​

Answer 1

$\it \mathbf{2.} \ \ \begin{cases}\it 3a+2b-c=6\\ \\ \it 2a-b+c=8|_{\cdot2}\end{cases} \Rightarrow \begin{cases}\it 3a+2b-c=6\\ \\ \it 4a-2b+2c=16\end{cases}\\ \\ .\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ ---------\\.\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 7a\ \ \ \ \ \ \ \ \ +c\ =22$

3.

$\it Vom\ nota\ cele\ trei\ numere\ cu\ a,\ b,\ c\\ \\ \dfrac{a+b+c}{3}=124 \Rightarrow a+b+c=372\ \ \ \ (1)\\ \\ \\ \dfrac{a+b}{2}=36 \Rightarrow a+b=72\ \ \ \ (2)\\ \\ \\ (1),\ (2) \Rightarrow 72+c=372|_{-72} \Rightarrow c=300$