If the value of the discriminant of a quadratic equation $kx^2 - 6x + 1 = 0$ is $0$,then $k = \ldots$

Values of $k$ for which the quadratic equation $2x^{2}-kx+k=0$ has equal roots is

If the value of the discriminant of a quadratic equation $6x^{2}-x-k=0$ is $25$,then $k = \ldots$

Is the following situation possible? If so,determine their present ages. The sum of the ages of two friends is $20$ years. Four years ago,the product of their ages in years was $48$.

Find the roots of the following quadratic equation,if they exist,using the quadratic formula: $x^{2}+4x+5=0$.

Find the discriminant of the following quadratic equation: $x^{2}-7x+10=0$