Using suitable identity, evaluate the following:

$101 \times 102$

Write the following cubes in expanded form

$(2 x+7)^{3}$

Multiply $x^{2}+4 y^{2}+z^{2}+2 x y+x z-2 y z$ by $(-z+x-2 y)$

The polynomial $p(x)=x^{4}-2 x^{3}+3 x^{2}-a x+3 a-7$ when divided by $x+1$ leaves the remainder $19 .$ Find the values of $a .$ Also find the remainder when $p(x)$ is divided by $x+2.$

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

$\pi x^{2}-\frac{22}{7} x+3.14$