Using a suitable identity,evaluate the following:
$103^{3}$

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: $x^{2}-15x+50$

Classify the following as a constant,linear,quadratic,or cubic polynomial:
$y^{3}-y$

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

Verify whether $3$ and $7$ are zeros of the polynomial $p(x) = x^{2} - 5x - 14$ or not.

Write the coefficient of $x^{2}$ in the following polynomial:
$\sqrt{5}x^{2} - 7x + 13$