For polynomial $p(x) = x^{3} - 3x^{2} + 8x + 12$,find the value of $p(-1)$.

Factorise the following:
$9 x^{2}-12 x+3$

Factorise $16 x^{2}+40 x y+25 y^{2}$.

Which of the following expressions is a polynomial? State the reason. If an expression is a polynomial,state whether it is a polynomial in one variable or not: $x^{2}-15x+50$

Factorise the following:
$\left(2 x+\frac{1}{3}\right)^{2}-\left(x-\frac{1}{2}\right)^{2}$

$85 \times 75 = \ldots \ldots \ldots$