Question

If one root of the quadratic equation 3x^2-kx+6=0 is 2, then the value of k is

Answer 1

putx=2, 3×2²-2k+6=0
12-2k+6=0
18=2k
k=9

Answer 2

Answer:

k=9

$x = 2 \\ \\ 3(2) { }^{2} - 2k + 6 = 0 \\ \\ 3 \times 4 - 2k + 6 = 0 \\ 12 - 2k + 6 = 0 \\ 18 - 2k = 0 \\ 18 = 0 + 2k \\ 18 = 2k \: \\ therfore \: \: 2k \: = 18 \\ k = \: \frac{18}{2} \\ therefore \: \\ k = 9$