On simplifying $4x^2 -3y^2 +2z^2 - 5x^2+2y^2-2x^2$ we get

Question

$\begin{array}{1 1} -x^2-y^2 \\ y^2-z^2 \\ x^2-y^2+z^2 \\ x^2+y^2 \end{array} $