Find the values of $k$ for which the following equation have equal roots:

$x^2-4kx+k=0$

$kx(x-2\sqrt{5})+10=0$

Find the values of $k$ for which the equation $kx(x-3)+9=0$ will have real and equal roots.

Find the values of $k$ for which the following equation have real and equal roots:

$4x^2+kx+3=0$

Find the values of $k$ for which the quadratic equation $k{x}^2+2x+1=0$ has real and distinct roots.

Find the values of $k$ for which the quadratic equation $k{x}^2+6x+1=0$ has real and distinct roots.

Find the least positive value of $k$ for which the quadratic equation $x^2+kx+4=0$ has real roots.