Question

Buna ziua! Ajutati-ma si pe mine la ex 14 a si b!​

Answer 1

a)

$\begin{cases}3x-6y-6-4x-2y+8+9=-15\\8x-4y+8-3x+6y+15-7=32\end{cases}$

$\begin{cases} - x - 8y = - 26\ \ \Big|\cdot 5\\5x + 2y = 16\end{cases}$

$\begin{cases} - 5x - 40y = - 130\\ \ \ \ 5x + \ \ 2y = \ \ \ \ \ 16\end{cases}$

$- 38y = - 114 \implies y = 3$

$- x - 8 \cdot 3 = - 26 \implies x = 2$

b)

$\begin{cases}-4x-2y+6+3x-9y+12+5=-8 \\4x+8y+12-6x-3y-15+7=23 \end{cases}$

$\begin{cases} - x - 11y = - 31\ \ \Big|\cdot (- 2) \\ - 2x + 5y = 19 \end{cases}$

$\begin{cases} 2x + 22y = 62 \\ - 2x + 5y = 19 \end{cases}$

$27y = 81 \implies y = 3$

$- x - 11 \cdot 3 = - 31 \implies x = - 2$