Question

va rog ajutati.ma la exercitiul 5 testul 3 dau coroana

Answer 1

$\left\{\begin{matrix} 2x + \frac{x + y}{2} = 4 \: | \times 2\\ \\ \frac{y - x}{2} + 3y = 10 \: | \times 2 \end{matrix}\right.$

$\left\{\begin{matrix} 4x + x + y = 8\\ y - x + 6y = 20\end{matrix}\right.$

$\left\{\begin{matrix} 5x + y = 8\\ - x + 7y = 20 \: | \times 5\end{matrix}\right.$

$\left\{\begin{matrix} 5x + y = 8\\ - 5x + 35y = 100\end{matrix}\right.$

$5x - 5x + y + 35y = 8 + 100$

$36y = 108$

$y = \frac{108}{36}$

$y = 3$

$5x + y = 8$

$5x + 3 = 8$

$5x = 8 - 3$

$5x = 5$

$x = \frac{5}{5}$

$x = 1$