
Christopher G. answered 08/07/13
Math Tutor - Algebra, Trig, Calculus, SAT/ACT Math
The polynomial you gave has two terms: the first is x3y2, and the second is -30x4. Using the definition you gave, the degree of the first term, x3y2, is 3 + 2 = 5, while the degree of the second term, -30x4, is 4. Therefore, the degree of the entire polynomial is 5.
The definition says that the degree of a polynomial is the largest of the degrees of the individual terms; you can't simply add the highest term of each variable in each term. You're thinking of taking the y2 of the first term and the x4 of the second and making that the total degree, but you can't separate terms like that to find the degree. I think what might be throwing you off is that there are two separate variables here, the x and the y, and you're trying to find the highest power of each of them instead of the individual terms.
Hope this helps!