Question

if x=3 is one root of the quadratic equation x2-2kx-6 =0. find the value of k?

Answer 1

x2-2kx-6=0

(3)2-2k3-6=0
9-6k-6=0
9-6k=6
-6k=6-9
-6k=-3
k=3÷6
k=1/2

Answer 2

X2-2x-6=0
X=3
(3)2-2(3)-6=0
9-6-6=0
3-6=0
6/3=0
1/2