Question

me ajuda pfvr? Dado o sistema 3×/x-y=4 e X-Y=8 a soma de x +y vale A)8. b)-6. c)10. d)6. e)-12​

Answer 1

{3x-y=4

{x-y=8. x=8+y

3 (8+y)-y=4. x-y=8. x+y=-2-10=-12

24+3y-y=4. x-(-10)=8

3y-y=4-24. x+10=8

2y=-20. x=8-10

y=-20/2. x=-2

y=-10

resposta: e)-12