What is the sum of x, y and z?
`x + y = 8`
`x + z = 11`
`y + z = 7`

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

Subtract the sum of 5x - 4y + 6z and -8x + y - 2z from the sum of 12x - y + 3z and -3x + 5y - 8z

Find the value of x,y and z:x+y+z=5,x-y+z=6,x+y-z=11

2x + 3y + z = 11, x + 2y + z = 8, x-y + z = 2

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 .

What is x(y - z) (y + z) + y(z - x) (z + x) + z(x - y) (x + y) equal to ?

x,y,z are moles used. sum of [x + y + z = 1]

Add the following: (i) x – 3y – 2z , 5x + 7y – 8z , 3x – 2y + 5z