Is it possible for a cubic polynomial function to have a zero?

A cubic polynomial can have only three roots or one root; a quadratic polynomial can have only two roots or zero roots.

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.