Question

resposta do sistema abaixo

{3x+2y=7
{x=5+2y​

Answer 1

{3x+2y=7

{x=5+2y​

{3x+2y= 7

{x-2y= 5 Corta os Y.

4x= 12

X= 12/4

X= 3

3x+2y=7

3•3+2y= 7

9+2y= 7

2y= 7-9

2y= -2

y= -2/2

y= -1

S= {3,-1}

Espero ter ajudado :)

Answer 2

Resposta:

$3x+2y=7~...~equacao~I\\\\ x=5+2y\\ \\ x-2y=5~...~equacao~II\\ \\ metodo~da~adicao~(some~as~equacoes)\\ \\ \\ ~~~~~~~~3x+2y=7\\ +~~~~~x-~2y=5\\ ~~~~~~~------\\ ~~~~~~~~4x+~~0=12\\ \\ 4x=12\\ \\ x=\frac{12}{4} \\ \\x=3\\ \\ substitua~(x=3)~em~uma~das~equacoes\\ \\ 3x+2y=7\\ \\ 3.3+2y=7\\ \\ 9+2y=7\\ \\ 2y=7-9\\ \\ 2y=-2\\ \\ y=-\frac{2}{2} \\ \\ y=-1\\ \\ \\ S~~\left \{ {{y=-1};~~ {x=3}} \}$