Answer :

Answer:

2ab

Step-by-step explanation:

I am pretty sure this is adding polynomials.

This is not correct.

ab-bc+0

ab+bc-ca

0+0+ca

If you take each row at a time, you get.

ab-bc+0

ab+bc-ca

=

2ab+0-ca

0+0+ca

2ab

2ab is your answer