Question

b) {2x + y = -3
{x + y = -1​

Answer 1

B) {2x + y = -3. (×-1)

{x + y = -1​

{ -2x- y= 3

{ x+y= -1

Corta os y.

-x= 2 (×-1)

X= -2

X+y= -1

-2+y= -1

Y= -1+2

Y= +1

S= {-2,1}

Espero ter ajudado ;)