Question

resolver o sistema 4x+y=0
6x-3y=36

Answer 1

Metodo da substituiçao: 4x+y=0 ==> y= -4x
a)
6x-3y=36
6x-(3* -4x)=36
6x -(-12x)=36
6x+12x=36
18x=36
x=36/18
x=2
b)
achando o y => y= -4x
y= - 4*2
y= -8

==> 4x+y=0
4*(2)+(-8) = 0
8 - 8 = 0

:)

Answer 2

Método adição:

$\left \{ {4x+y}=0~~*(6) \atop {6x-3y=36~~*(-4)}} \right. \\ \\ \left \{ {{24x+6y=0} \atop {-24x+12y=-144}} \right. \\ \\18y=-144\\ \\\boxed{y=-8}\\ \\4x+y=0\\ \\4x=-y\\ \\x= \frac{8}{4}\\ \\\boxed{x=2}$