Answer: [tex]-x^{2} -y^{2} -z^{2}[/tex] or [tex]-(x^{2} +y^{2} +z^{2} )[/tex] for the second one make sure to not forget the minus sign outside the bracket...
Step-by-step explanation: So the equation is [tex]x^{2} -y^{2} -z^{2} +y^{2} -z^{2} -x^{2} +z^{2} -x^{2} -y^{2}[/tex]
Now you need to bring together all the like terms..
[tex](x^{2} -x^{2} -x^{2} ) + (-y^{2} +y^{2} -y^{2} ) + (-z^{2} -z^{2} +z^{2} )[/tex]
Now simplify..
[tex]-x^{2} -y^{2} -z^{2}[/tex]
