Question

{ x+y = -7\\
{3x - 2y + 4

qual o valor?

Answer 1

Resposta:

$\left \{ {{x +y = -7} \atop {3x - 2y = 4}} \right.$

x + y = -7 *(-3)

3x - 2y = 4

-3x - 3y = 21

3x - 2y = 4

-5y =25

y = -25/5

y = -5

x + y = -7

x -5 = -7

x = -7 + 5

x = -2