If one zero of the quadratic polynomial $x^{2}+3x+k$ is $2$,then the value of $k$ is

Find the zeros of the following quadratic polynomial: $-21x^2 + 16x + 5$.

If the zero of the polynomial $p(x) = ax^2 - 11x + 3$ is $1$,then $a = \ldots$

The zeros of the cubic polynomial $p(x) = ax^3 + bx^2 + cx + d$ where $a \neq 0$ and $a, b, c, d \in R$ are $\alpha, \beta,$ and $\gamma$. Then $\alpha \beta \gamma = \dots$

Prove that $-6, -\frac{1}{2}$ and $1$ are the zeros of the cubic polynomial $p(x) = 2x^3 + 11x^2 - 7x - 6$. Also,verify the relationship between the zeros and the coefficients.

Find the zeroes of the quadratic polynomial $4s^{2}-4s+1$ and verify the relationship between the zeroes and the coefficients.