Factorise x(x2+y2-z2) + y(-x2-y2+z2)-z(x2+y2-z2)

Factorise $x (x^{2} + y^{2} - z^{2}) + y (- x^{2} - y^{2} + z^{2)} - z (x^{2} + y^{2} - z^{2})$

Match the items on the right to the items on the left.

step 1

step 2

step 3