Question

resolva os sistemas
3x+y=8
2x-2y=0

Answer 1

Olá.

Resposta: 

3x+y=8
2x-2y=0

y=8-3x.

Sendo assim:

2x-2(8-3x)=0 
2x-16+6=0
2x=0+16-6
2x=-10
x=-5

Sendo assim: 

3x+y=8
3.(-5)+y=8
-15+y=8
y=8+15

y=23

Espero ter ajudado. Bons estudos. 

Answer 2

olá, boa noite....
3x+y=8⇒ isola o y ..y=8-3x
2x-2y=0 depois substitui no segundo sistema assim 2x-2(8-3x)=0
                                                                                   2x-16-6x=0
                                                                                    2x-6x=16
                                                                                      -4x=16
                                                                                        x=16÷-4
                                                                                         x=12