Question

Rezolvati sistemul ... -2x+3y=11 7x+y=-4 Dau Coroana;

Answer 1

$\left\{\begin{matrix} - 2x + 3y = 11\\ 7x + y = - 4 \: | \times ( - 3) \end{matrix}\right.$

$\left\{\begin{matrix} - 2x + 3y = 11\\ - 21x - 3y = 12\end{matrix}\right.$

$- 2x - 21x + 3y - 3y = 11 + 12$

$- 23x = 23 \: | \div ( - 23)$

$x = -1$

$7x + y = - 4$

$7 \times(- 1 )+ y = - 4$

$-7 + y = - 4$

$y = - 4 + 7$

$y = 3$