Factorise :

$x^{2}+9 x+18$

Evaluate using suitable identities : $(998)^{3}$

Classify the following as linear, quadratic or cubic polynomial

$4 x^{2}-49$

With the help of the remainder theorem. examine whether $x+2$ is a factor of the polynomial $x^{3}+9 x^{2}+26 x+24$ or not.

If $p(x)=x^{4}-2 x^{3}+3 x^{2}-a x+3 a-7$ is divided by $(x+1),$ then the remainder is $19 .$ Find the value of a. Also, find the remainder, when $p(x)$ is divided by $(x+2)$