Question

Solve (x – y) (x + y) + (y –z) (y + z)+ (z – x) (z +x)

please answer ASAP​

Answer 1

= x 2 + xy - xy -y2 + y2 + yz - yz - z2 + z2 + zx - zx- x2

= 0

2 means square

Answer 2

Answer:

$(x + y)(x - y) = {x}^{2} - {y}^{2}$

$(y +z )(y - z) = {y}^{2} - {z}^{2}$

$( z- x)( z+ x) = {z}^{2} - {x}^{2}$

$(x + y)(x - y) + (y - z)(y + z) + (z - x)(z + x) =$

${x}^{2} - {y}^{2} + {y}^{2} - {z}^{2} + {z}^{2} - {x}^{2}$

$==>0$