Write the coefficient of $x^{2}$ in the following polynomial:
$7 x^{3}-11 x+24$

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: $x^{2}+2xy+y^{2}$

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

Classify the following as a constant,linear,quadratic,or cubic polynomial:
$4-5 y^{2}$

If $49 x^{2}-b=\left(7 x+\frac{1}{2}\right)\left(7 x-\frac{1}{2}\right),$ then the value of $b$ is

With the help of the remainder theorem,find the remainder when the polynomial $x^{3}+7x^{2}+17x+25$ is divided by $x+4$.