The roots of a quadratic equation $x^{2} = 49$ are ..... .

Find the roots of the following quadratic equation by using the quadratic formula,if they exist: $x^{2}-5x-1=0$

Verify whether the given value of $x = 2$ is a solution of the quadratic equation $\frac{1}{x+4} - \frac{1}{x-7} = \frac{11}{30}$ or not.

If $x=-2$ is a solution of a quadratic equation $k x^{2}+5 x+2=0,$ then $k=\ldots \ldots \ldots \ldots$

Obtain the roots of the following quadratic equation by using the quadratic formula: $9x^{2} + 7x - 2 = 0$.

The quadratic equation .............. has a root $x=3$.