Degree of an Algebraic Expression

Write the degree of the following polynomial.

$\mathrm{m}+{\mathrm{a}}^4\mathrm{m}+{\mathrm{a}}^5{\mathrm{m}}^3-{\mathrm{m}}^2-{\mathrm{a}}^4{\mathrm{m}}^7$

Write the degree of the following polynomial.
$\mathrm{a}+{\mathrm{a}}^3-{\mathrm{a}}^0$

Write the degree of the following polynomial.
$\mathrm{p}+{\mathrm{p}}^3+{\mathrm{p}}^7$

Arrange the terms of the following algebraic expressions in the descending order of their powers.
$-3{\mathrm{a}}^2\mathrm{b}+5\mathrm{ab}+5{\mathrm{a}}^2{\mathrm{b}}^2-4{\mathrm{ab}}^3+6{\mathrm{a}}^7{\mathrm{b}}^2$

Arrange the terms of the following algebraic expression in the descending order of their powers.

$-2{\mathrm{x}}^2{\mathrm{y}}^2+3{\mathrm{x}}^3{\mathrm{y}}^2+5\mathrm{xy}-4{\mathrm{x}}^3{\mathrm{y}}^3$

Arrange the terms of the following algebraic expression in the descending order of their powers.
$5{\mathrm{p}}^3+6{\mathrm{p}}^7-3{\mathrm{p}}^2-1$

Arrange the terms of the following algebraic expression in the descending order of their powers.
$3x^2+1-4x^4+4x^3$