Question

X + y - 6z = 0.....(i)
x - y - z = -1.....(ii)
x + y + z = 21....(iii)

kerjain dengan metode campuran...

Answer 1

* x+y-6z=0
  x-y-z=-1
  -------------  -
 2y-5z= 1

* x-y-z= -1
  x+y+z= 21
-------------------- -
-2y-2z= -22

* 2y-5z= 1
  -2y-2z= -22
--------------------- +
-7z= -21
z= 3

*2y-5z= 1
 2y-5(3) = 1
y= 8

* x-y-z= -1
 x-8-3= -1
 x= 10