please help me factor this
+ 2xy- 3x-y2
A "trinomial" has three terms; then the prefix "tri", meaning "three". The posted polynomial has six terms.
However, you may convert this to trinomial factorization by noting the common factor in the first three terms and the common factor (being -1) in the last three terms. Factor the two trinomials which result. The two share one common factor. You can factor this out, and then simplify the remaining terms, etc.