Classify the following as linear, quadratic or cubic polynomial

$4 y+11$

Classify the following polynomials as polynomials in one variable, two variables etc.

$y^{3}-5 y$

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

$x-2$

If $x+2 a$ is a factor of $x^{5}-4 a^{2} x^{3}+2 x+2 a+3,$ find $a$

Factorise

$9 x^{2}-21 x y+10 y^{2}$