Question

a) {-x+y=90
2x+y=-8​

Answer 1

Explicação passo-a-passo:

-x+y=90 . (2)

2x+y=-8

____________

-2x+2y=180

+2x+y= -8

____________

2y+y=180-8

3y=172

y=172/3

-x=90-y

-x=90-172/3

-x=(270-172)/3

-x=98/3

x=-98/3

Resposta :

S={( -98/3 , 172/3)}