Working with the equation 5x2 - 3x4 - 5 + x, you would drop the constants and coefficients to get x2 - x4 + x.

x5y3z + 2xy3 + 4x2yz2

deg(x5y3z) = 5 + 3 + 1 = 9 deg(2xy3) = 1 + 3 = 4 deg(4x2yz2) = 2 + 1 + 2 = 5