Question

X-y+z+2=0
2x+y+3z-1=0
x+y-z-4=0

Tentukan nilai x, y dan z !!!

Answer 1

(-)Eliminasi
pers 1dan2
x-y+z=-2 ×2 = 2x-2y+2z=-4
2x+y+3z=+1 ×1 = 2x+y+3z=+1 _
-3y-z=-5. pers 4
pers 2dan3
2x+y+3z=+1 ×1 =2x+y+3z=+1
x+y-z=+4 ×2 =2x+2y-2z=+8 _
-y+5z=-7. pers 5-
pers 4dan5
-3y-z=-5 ×1 =-3y-z=-5
-y+5z=-7 ×3 =-3y+15z=-21 _
-16z=+16
z=16:-16
z=-1
(-)Substitusi
pers 3
-3y-z=-5
-3y-(-1)=-5
-3y+1=-5
-3y=-5-1
-3y=-6
y=-6:-3
y=2

pers 1
x-y+z=-2
x-2-1=-2
x-3=-2
x=-2/-3 (sama" dikali -1)
x=2/3