Tentukan hp dr persamaan x+y=1 , y+z=-1 , x+z=6

Soal
x + y = 1
y + z = – 1
x + z = 6

x + y = 1
y + z = – 1
—————- –
x – z = 2

x – z = 2
x + z = 6
————— +
2x = 8
x = 4

x + y = 1
(4) + y = 1
y = 1 – 4
y = – 3

y + z = – 1
(-3) + z = – 1
z = – 1 + 3 = 2

Hp (x, y, z) adalah (4, -3, 2)