tolong jawabannya yaa please....?

No.2 memakai cara eliminasi

 2x + y          = -7
 -2x + 6z       = -10 (dikalikan dua)
_______________________ +
Y+6z = -17 ...... (1)

      2Y + Z     = -1
      2Y + 12Z = -34 (dikalikan dua)
  __________________________ -

-11 Z = 33 , Z=-3

2y+Z = -1 
2Y - 3 = -1 , 2Y= 2 , Y=1

2x + y = -7 
2X + 1 = -7 , 2X = -8 , X=-4

HP {-4,1,-3}