Factorise each of the following

$27 x^{3}-8 y^{3}-54 x^{2} y+36 x y^{2}$

Write the coefficients of $x^{2}$ in each of the following polynomials

$3 x^{3}-8 x^{2}+14 x-5$

Expand

$(2 x-3)(2 x+5)$

Find $p(-2)$ for the polynomial $p(x)=5 x^{2}-11 x+3$

If $x+1$ is a factor of $a x^{3}+x^{2}-2 x+4 a-9,$ find the value of $a$.