If $x^{51}+51$ is divided by $x+1,$ the remainder is

If $(5 x-3)^{2}=25 x^{2}+k x+9,$ then find $k$

Factorise

$x^{3}+8 x^{2}+9 x-18$

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

$x^{3}+y^{3}+z^{3}-3 x y z$

Classify the following as a constant, linear,quadratic and cubic polynomials:

$y^{3}-y$

The following expressions are polynomials? Justify your answer:

$\sqrt{3} x^{2}-2 x$