2x + z = 5 . Y - 2z = -3 . X + y = 1 . Tentukan x.y.z ... Beserta caranya ....

Bab Persamaan Linear
Matematika SMA Kelas X

y + x = 1
y - 2z = -3
--------------- -
x + 2z = 4
x = 4 - 2z

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2x + z = 5
2 (4 - 2z) + z = 5
8 - 4z + z = 5
-3z = 5 - 8
z = -3 : -3
z = 1

x = 4 - 2z
  = 4 - 2 . 1
  = 4 - 2
  = 2

y + x = 1
y + 2 = 1
y = 1 - 2
y = -1

jadi, x = 2
       y = -1
       z = 1

2x + z = 5
2x + 2y = 2
diperoleh -2y + z = 3
2y + z = 3
2y - 4z = -6
diperoleh 5z = 9 z = 9/5
2x = 16/5 x = 16/10
y = -6/10