Final answer:
Statement A is incorrect, while statements B and D are correct regarding Pascal's Triangle.
Step-by-step explanation:
Statement A is incorrect. The nth row of Pascal's Triangle gives the coefficients in the expansion of (x+y)n, not (x+y)n-1.
Statement B is correct. The method for generating Pascal's Triangle is to add adjacent terms on the preceding row to determine the term below them.
Statement C is incorrect. Pascal's Triangle can be used to expand binomials with both positive and negative terms.
Statement D is correct. The nth row of Pascal's Triangle gives the coefficients in the expansion of (x+y)n.