Factorise ab(a2+b2-c2) + bc(a2+b2-c2)-ca(a2+b2-c2)

Factorise $a b (a^{2} + b^{2} - c^{2}) + b c (a^{2} + b^{2} - c^{2)} - c a (a^{2} + b^{2} - c^{2})$

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

step 1

step 2