Question

if x=3 is one root of the quadratic equation x^2-2kx-6=0

Answer 1

k=1/2 is the answer of quadratic equation

Answer 2

just to subsitute 2 in place of x
:=2^2-2*2*k-6=0
:=4-4k-6=0
:=-2-4k. =0
2+4k=0
4k=-2
k=-1/2(answer)

I hope this will help you