Question

Resolução

{x+y=-3
{3x+y=1

Answer 1

{x+y=-3 (i)
{3x+y=1   (ii)

(i)-(ii)

-2x+0 =-4

-2x=-4

x=2

x+y=-3 ==> 2+y=-3  ==>y=-5

Answer 2

{x+y=-3
{3x+y=1
_________/////
{x+y=-3
x=-3-y
_________/////
{3x+y=1
3.(-3-y)+y=1
-9-3y+y=1
-2y=1+9
-2y=10 (-1)
2y=-10
Y=-10/2
Y=-5
_________///////
x=-3-y
x=-3(-5)
x=-3+5
x=2
X = 2 e Y = -5