x+y+z=6
x + 2z =7,
3x + y + z = 12

Solve using matrices, for x,y and z: 2x-y-z = 7, 3x+y - z = 7, x + y - z = 3.

Find the angle between the planes : (i) 3 x - 6y - 2z = 7 " " 2x + y - 2z = 5 (ii) 4 x + 8y + z = 8 " " and y + z = 4 (iii) 2 x - y + z =6 " " and x + y + 2z = 7 .

The system 2x + 3y + z= 5, 3x + y + 5z =7, x + 4y -2z=3 has

2x + 3y-5z = 7, x + y + z = 6,3x-4y + 2z = 1, then x =

Solve the system: x + y - 2z = 0, 2x - 3y + z = 0, 3x - 7y + 10z = 0, 6x - 9y + 10z = 0.