If the discriminant of $x^{2}-10x+(2k-1)=0$ is $40$,then $k=$...............

Find the discriminant of the following quadratic equation: $4x^{2} - 12x + 9 = 0$.

The value of the discriminant of the quadratic equation $x^{2}-8x+15=0$ is ...... .

State whether the following statement is 'True' or 'False'. Justify your answer: If in a quadratic equation the coefficient of $x$ is zero,then the quadratic equation has no real roots.

In quadratic equation $ax^{2} + bx + c = 0$,where $a \neq 0$,$b = 0$,and $D > 0$,then both the roots of the equation are .....

If one of the roots of $2x^{2} + 5x + 3 = 0$ is $-1$,the other root is .............