What is negative nine multiplied by negative four y to the zero power?

Answer 1

If you mean (-9 x -4)^0, then the answer it 36^0 = 1.

Otherwise, if you mean -9 x -4^0, then the answer is -9 x 1 = -9

The answers above assume that your "y" is a typo. If not, the answers are still the same:

(-9 x -4y)^0, then the answer it 36^0 = 1.

Otherwise, if you mean -9 x -4y^0, then the answer is -9 x 1 = -9