Question

sistema {6x-y=4

                {2x+3y=-2

Answer 1

(a)    6x -    y = 4
(b)    2x + 3y = -2

De (a)  

y = 6x - 4   (c)

Substituindo em (b)

2x + 3 (6x - 4) = -2

Resolvendo:

2x + 18x - 12 = -2
20x = 10
x = 1/2

Logo, substituindo em (c)

y = 6. 1/2 - 4
y = 3 - 4
y = -1

Answer 2

$\left \{ {{6x-y=4~(-2)} \atop {2x+3y=-2~.(6)}} \right.$

$\left \{ {{-12x+2y=-8} \atop {12x+18y=-12}} \right. \\ \\20y=-20\\y=-20\div20$

$\boxed{y=-1}$

Substituindo o valor de y

$6x-y=4\\ \\x= \frac{4+y}{6}$

$x= \frac{4-1}{6}$

$\boxed{x= \frac{1}{2} }$