Determining the degree of a polynomial with more than one variable:
1) Add the exponents of each variable in each term:
3x³ = 3
2x = 1
[tex]-zx ^{4} =1+4 = 5[/tex]
2) The term with the largest sum of exponent determines the degree of the polynomial:
[tex]-zx ^{4} [/tex] has the largest sum of exponents: 5
Therefore:
[tex]f(x)=3x ^{3} +2x-zx^{4} [/tex] has a degree of 5, or the equation is in 5th degree.