no.8 yang tahu tolong bantu.pakai jalan subsitusi.

I. 2x - y + 3z = -4  ----> y = 2x + 3z + 4
II. x + 2y - 5z = 11
III x + 3y - 2z = 5

I dan II
x + 2(2x + 3z + 4) - 5z = 11
x + 4x + 6z + 8 - 5z = 11
x + 4x + 6z - 5z = 11 - 8
5x + z = 3 -------1 --------> z = 3 - 5x

I dan III
x + 3(2x + 3z + 4) - 2z = 5
x + 6x + 9z + 12 - 2z = 5
x + 6x + 9z - 2z = 5 - 12
7x + 7z = -7
x + z = -1 -------- 2

1 dan 2

x + (3 - 5x) = -1
x - 5x = -1 - 3
-4x = -4
x = 1

z = 3 - 5x
z = 3 - 5(1)
z = -2

y = 2x + 3z + 4
y = 2(1) + 3(-2) + 4
y = 2 - 6 + 4
y = 0

HP {1 ; 0 ; -2}