Question 485567
If you mean


*[tex \LARGE 2x^3y + 7xy - 9y]


the degree is 4 (leftmost term has degree 3+1 = 4).



Or, if you mean


*[tex \LARGE 2x3y + 7xy - 9] then the degree is 2; or if it's *[tex \LARGE 2^x3^y + 7xy - 9y] then it is not a polynomial in x or y; degree is zero.