ada yg tau gak ini jawabanya apa?? tentang persamaan linear

Bab Persamaan Linear
Matematika SMP Kelas VII

1] 2x + y = 6
      x + y = 2
  ---------------- -
           x = 4

x + y = 2
y = 2 - 4
y = -2 

HP = {(4, -2)}

2] 2x + y = 6
    y = 6 - 2x

x + 2y = 4
x + 2(6 - 2x) = 4
x + 12 - 4x = 4
-3x = 4 - 12
x = -8/-3
x = 8/3

y = 6 - 2x
y = 6 - 2 . 8/3
y = 6 - 16/3
y = (18 - 16)/3
y = 2/3

HP = {(8/3, 2/3)}