Question

Resolva os sistemas
x+y=-1
3x-y=3

Answer 1

x+y=-1
x=-1-y

3x-y=3
3.-1-y-y=3
-3-2y=3
-2y=3+3
-2y=6
y=6/-2
*y=-3*

x+y=1
x+(-3)=1
x-3=1
x=4

PROVA REAL
x+y=1
4+(-3)=1
4-3=1
1=1

Answer 2

Olá,

Resolução :

x+y=-1  => y =  - 1 - x
3x-y=3

4x = 2

x = 2/4 : 2  = 1/2


y = - 1 - x

y = -1 - 1/2

y = - 3/2


Bons Estudos!!