Find the zeroes of the polynomial in each of the following:
$h(y) = 2y$

Factorise the following quadratic polynomial by splitting the middle term:
$x^{2}-4x-77$

Which of the following expressions are polynomials in one variable and which are not? State reason for your answer. If the given expression is a polynomial,state whether it is a polynomial in one variable or not: $x^{2}+2xy+y^{2}$

Factorise the expression: $\frac{x^{2}}{4}+\frac{3 x y}{5}+\frac{9 y^{2}}{25}$

Write whether the statement is True or False. Justify your answer.
The degree of the sum of two polynomials each of degree $5$ is always $5$.

Factorise $x^{2}+9 y^{2}+4+6 x y+12 y+4 x$.