Write the degree of the following polynomial: $x^{8}-6561$.

Which of the following expressions is a polynomial? State the reason. If an expression is a polynomial,state whether it is a polynomial in one variable or not: $3x^2 + 5x - 7 + \frac{8}{x}$

Write the degree of the following polynomial:
$11-2 y^{2}$

Find the quotient and the remainder when $2x^2 - 7x - 15$ is divided by $x - 2$.

For the polynomial $p(x),$ if $p(7)=0,$ then .......... is a factor of $p(x)$.

If $x+y=-4,$ then what is the value of $x^{3}+y^{3}-12xy+64?$