Answer:
x +3y - 3z = 12
3x - y + 4z = 0
-x + 2y - z = 1
D = - 25
Dx = - 75
Dy = - 25
Dz = 50
x = Dx / D = - 75/(-25) = 3
y = Dy / D = -25 / (-25) =1
z = Dz / D = 50 /(-25) = -2
Answer: x=3 , y =1 , z = - 2
