Factorise each of the following
$27 x^{3}-64-108 x^{2}+144 x$
Factorise $: x^{3}-125$
If $x+y=-4,$ then what is the value of $x^{3}+y^{3}-12 x y+64 ?$
Give possible expressions for the length and breadth of a rectangle whose area is given as $\left(20 x^{2}+22 x+6\right)$ square units. $(x>0)$
Factorise each of the following
$27 x^{3}-8 y^{3}-54 x^{2} y+36 x y^{2}$