x^(2)-y^(2)-4xz+4z^(2)

Find the following produts: (i) (x+y+2z)(x^(2)+y^(2)+4z^(2)-xy-2yz-2xz)(2x-y+2z)(4x^(2)+y^(2)+9z^(2)+2xy+3yz-6xz)

Factorise 4x^(2) + y^(2) + z^(2) - 4xy - 2yz + 4xz .

If xy+yz+xz=1, then prove that (x)/(1-x^(2))+(y)/(1-y^(2))+(z)/(1-z^(2))=(4xyz)/((1-x^(2))(1-y^(2))(1-z^(2)))

Factorise : 2x^(2) + y^(2) + 8z^(2) - 2sqrt(2)xy + 4sqrt(2)yz - 8xz

If x^(2) + 3y^(2) + 4z^(2)+ 19 = 4 sqrt(3) ( x + y + z) , then the value of ( x - y + 4z) is: