For the polynomial $p(x) = x^{2} - 7x + 12$,find the value of $p(2)$.

Factorise the following quadratic polynomial by splitting the middle term:
$6 x^{2}+7 x-20$

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: $x^{2}-8x+15$

Classify the following as linear,quadratic,or cubic polynomial: $4y + 11$.

Factorise: $x^{3}+x^{2}-4x-4$

Factorise:
$84 - 2r - 2r^2$