Question

ajutor la c si d ex 5 algebra​

Answer 1

Explicație pas cu pas:

c)

$\begin{cases}2x + 3y = -3 \\-x + 2y = 5 \ \Big| \cdot 2 \end{cases} \iff \begin{cases}2x + y = 0 \\-2x+4y = 10 \end{cases}$

$3y + 4y = -3+10 \iff 7y = 7 \\ \implies \bf y = 1$

$2x + 3 = -3 \iff 2x = -6 \\ \implies \bf x = -3$

d)

$\begin{cases}2x - y = -1\ \Big| \cdot (-2) \\3x - 2y = 0 \end{cases} \iff \begin{cases}- 4x + 2y = 2 \\3x - 2y = 0 \end{cases}$

$-4x+3x = 2+0 \iff -x = 2 \\ \implies \bf x = -2$

$2(-2) - y = -1 \iff y = -4+1 \\ \implies \bf y = -3$